All good suggestions.
I haven't toyed with threading all that much other than the Fenceposts extension but it's always a pain in rear to handle it properly. Granted the preview generation happens quite quickly and we haven't seen much in the way of slowdown. (Excepting huge piles of text.)
I'll likely run this by
@Neobeo as I'm not too well versed with threading, especially with async/await. I don't understand how that pattern works at all. Don't have a mental picture of it... (even though I passed the C# certification which includes async/await, I have no idea how to apply it)