Thank you very much for a so quick new update and very specially for emphasize about performance.
I've found a problem related to symbols and booleans, tho... It's simple, if I create a simple nondestructive boolean and I make a symbol of the resulting "Compound" object, instances don't get updated in viewport when you make changes like translate points, etc, while for simple symbols not containing any booleans at all, changes are propagated instantly and as expected. Also, I've been getting some crashes while manipulating this kind of objects and/or their symbols that I'd say well could be related (one crash report at least, the one I obtained while saving, has been already sent to you by means of the application when asked).
I could attach a simple sample file if needed. BTW... is there a preferred way to make attachments here? I thought I could directly upload them by means of some forum functionality, but I'm not able to find it yet * ...Anyway, I hope it helps and greetings!
* OK, I figured it out :), so there it is the try me... Just create a symbol based on the Compound object and then insert it anywhere. Select the "Node Tool" and start translating some points or handles of the original. You'll see how changes are not real-time propagated, even the "Sync" button is (of course) pressed.
AD1.5.0.10W_symbols-&-booleans_20160806-0239_try-me.afdesign