@gregmoore Honestly, the biggest “incompatibility“ I’ve built into mine is shortcodes. They’re useful no doubt but at a price of lock-in, as you’re forced to carry them forward with every single theme. If you don’t maintain the templates your site will fail to build when you switch themes. This is ignoring whatever styling you were using would be out of place in the new theme, assuming it would even make sense at all.
I guess the latter could be avoided by making sure you have no shortcodes that are targeted by CSS, but you’d still have to port each template going forward.