I will of course be happy to see VST3 support in VePro.
In any case, as a work around for now, I recommend KushView Element to use inside VePro for hosting VST3 instruments. This plugin is free if you want to compile it yourself, or I think $2 to buy the most recent build of it. And worth EVERY penny. it works fine in VePro, most of the other similar products have various problems (ie, BlueCatAudio Patchwork, PlogueBidule, DDMF, etc).
You can host VST3 plugins inside it, though many of the so called "advantages" of VST3 will not really be utilized that way. Merely hosting VST3 is not that hard, but what instruments in particular are only VST3 or do you need to use VST3 for? The VST3 concept has some cool features utilized by Cubase, etc..but building all that fancy support into any hosting DAW is very non-trivial... and I'm not really sure right now which of those features would be useful if hosted directly in VePro, for example.
If you have an instrument that only comes in a VST3 version (which may increasingly be the case due to Steinberg's licensing rules), then the above work around can keep you going for now.
See attached image showing Element used inside VePro with a VST3 instrument.