My extension isn’t in the list, what should I assume?

Treat it as ? Unknown: assume it might need work until proved otherwise. The fastest way to lock the verdict is a 2-hour spike, install the extension on a Hyvä staging copy, click through the customer flows, screenshot any visual or functional gaps. That gives you the verdict, the porting effort, and the risk profile. If you have several unknowns, send the list via the audit form below and I’ll spike the lot in a single day.