Talking to a few people and I've heard about issues with rotten dog boards (nostly the replacement PSU side) and they are not that loved.
I've got a Jungle Lord with board issues and have managed to get a Pinball Technologies NW7 replacement board with covers the MPU, driver and sound board in one but not managed to get round to installing it yet so can't say how good are. JL is also System 7 and don't think the rotten dog boards work with S7 anymore. I had to email the maker to get one and they sent me an invoice, couldn't get it directly on a site.
There is also an DIY FPGA version that there are plans for with just replaces the MPU and Driver board so you need a working sound card or DIY alternative, the only issues with these are you have to have them built yourself as batch of 5 minimum for the board and then get the FPGA separately but last time I check they were fairly reasonably priced to the point where it would be cheaper to replace the main board than pay someone to replace a failed components on one, I'm sure it was something like £50 ish per board and then the FPGA price on top. The boards when built are mostly surface mount components with some socketed logic chips but the surface mount chips likely to fail be damaged have through hole sections on the PCB to make replacement easier.
https://www.lisy.dev/willfa7.html
There is also Williams Sys11 system in progress as well.
A third option which I think is a bit more work is the Arduino Pinball Controller (APC) which covers a lot of different machine boards it can replace. (Plans and links on the same lisy. Dev site as above.)