Due to things changing and me needing to split my time differently, I'm not sure what the roadmap is. There's a bunch of work done on v4, and I need to figure out whether I scale back on the initial 4.0 and ship it, try and roll those features into a 3.x and ship it, or wait until I've got more of 4.0 done.
There's been some talk of compat issues with PHP 7.4, so I'd want to track those down and see what can be patched.
drewm with my business hat on I would say ship an initial V4.0 sooner rather than later, this will breath (with all respect, because I really respect what you have made over the last 10 years) life into the product / create excitement. If it's paired with the new subscription model it may help the revenue which could allow you to have extra resources to develop new releases quicker, updates, documentation etc. Just my 2 cents but it is what I would do.
I would also say Perch Shop should be a paid add-on. At the moment we can literally build a shop on a £60 Perch License. Compared to something similar like Craft I would say Perch is currently undervalued / too cheap.