Welcome to the forum. 

VSL has never offered articulation sets for Logic, even when the number of dimensions was three or less. 

Do a search on "Audiogrocery XDAW." This is a third party program designed to accommodate far more than three  keyswitches. Its developer, Ivan, is very responsive to users' questions. There is, however, a learning curve. 

XDAW allows three different ways to create articulation sets. It can be used as a simple builder of three-switch Art sets, in which case you just save the set in Logic's correct folder. You could build the very same thing in Logic, but XDAW has features to expedite the build. However, because of the very issue you mention, a straight-forward Logic Art set, no matter where or how it was built, only drives three keyswitches -- hence no Synchron String Pro / Elite. 

The last two ways include automation and the use of Scripter. Either of these two is required for more than three keyswitches. (You don't have to know how to write scripts.)

I rebuild my templates frequently. Sifting Synchron Pro / Elite Strings into no more than three dimensions is a challenge, especially if you want to preserve all the options. It's a great way to learn the library and the Synchron Player. But it does take time. 

If you pursue XDAW, ask Ivan if he has any pre-made Synchron files. 

Telemachus, I endorse Plowman's recommendation of Audiogrocery; Ivan is certainly no Johnny-come-lately, he knows what he's doing - his XDAW is the most sophisticated solution I've yet found for LPX articulation switching.

It's not true to say "new synchron libraries such as elite strings are configured with up to 6 keyswitches/messages and therefore their patches are unusable with logic pro". LPX users don't have to use Articulation Sets, nor indeed any other fancy techniques aimed at making articulation switching more slick and convenient.

For various technical reasons related to my own very specific LPX configuration, I've recently reverted to controlling all Synchron Player dimensions and patches one by one, directly using the keyswitches and CCs already set up by VSL. Yes at times it can be a bit of a slog, but it is sensible and straightforward.

And BTW, VSL's SyzDimension Strings - which is my beloved go-to library - uses up to 8 dimension columns.

you are correct that LogicPro unfortunately only offers three keyswitches per articulation, it used to only offer one!

But still three is often not enough. You can write your own Scripter scripts. Its actually not that difficult to write a simple scripter script that will insert 5-6 keyswitches per articulation ID. I can do a tutorial on that if there is enough interest. Its obviously not as easy as adding them directly to the articulation set, but once you do one script like this, the 2nd and 3rd scripts would be relatively easy. I can write a script in literally 10 minutes that will handle the keyswitches for a Synchron instrument...its not a big deal...but it does require a little bit of scripting prowess, which a lot of orchestrators don't have and don't have any inclination to learn...so I get that...

@Telemachus said:

Hello,

I am looking for a workaround with as minimal configuration effort and as close to the original synchron presets as possible.

Another option if you’re not wedded to Logic Pro is to use Studio One, where VSL has recently used S1’s Sound Variations API so that all the articulations are automatically available to you for all Synchron and Synchron-ized products. 

See https://www.vsl.co.at/en/News/VSL_StudioOnehttps://www.vsl.co.at/en/News/VSL_StudioOne 

I switched from Logic to S1 for this reason (admittedly as a newbie, so I hadn’t invested a lot of effort into Logic).  But S1 is very intuitive, and it’s incredible to be able to have all of Synchron Strings Pro’s 127 articulations available instantly.  Or the 3420 artics of Sy Dim Strings I ! (well, that eye popping number is because of the 6 string position options and 8 group configurations.)  Not to sound like a shill for S1, but you can try it for a month for $15.

Still crying wolf, xxx (aka the dude who has the answer to life, the universe and everything, lol)? Of course you didn't mention that Ivan gave you the spanking you deserved for trying to publicly trash his good product and good professional reputation. In your world of one, nobody is allowed to take offence at your offences uh?

Here is a short tutorial I posted on the LogicForum 10 months ago with an example script for handling keyswitching using LogicPro Scripter.

https://www.logicprohelp.com/forum/viewtopic.php?f=45&t=149373&p=781561&hilit=keyswitch#p781561

It can easily be expanded to as many keyswitches per articulationID as you want.

I am going to post a little more info to that thread today also..  I would post these tips directly here, but this forum has very limited formatting options so its easier to explain more clearly at the other one dedicated to LogicPro.

for that, check out the input "switch" section of the articulation set.  You can set it up so that as you play in your parts, you hit some designated keyswitches (which do not necessarily need to match the output keyswitches)...and by those keyswitches, LogicPro will automatically assign an articulationID to each note as you play it in.  Check that out and see where you get, if you are comfortable with performing the keyswitches that way, its a nice way to play in your part and end up with articulationID's in your track instead of embedded keyswitches.

also, when you use the input switch mechanism to automatically assign art id's as you perform....the notes getting assigned articulationID's will echo THRU the script and into your instrument...so... what I mean is you can use whatever set of keyswitches you want for performing the parts in and assigning art id's based on those keyswitches...  Then LogicPro will echo those notes through the articulation set output section which ordinarily might include completely different keyswitches then whatever was used for the input.....or...in this case if you are going to use a script, then leave the articulation set OUTPUT section blank...and the script will add those output keyswitches..including while you're performing it in...you'll hear the correct articulation as you play because that mechanism will do it both while you perform it and later when you play it back...based off the articulationID.

Hope that makes sense.