I can completely understand -- I have been developing personal projects for decades now and I have an extremely strong sense of what I what to achieve and need very little in the way of outside direction.
But it sometimes good for someone to provide a view that is totally upside-down to the way you would do things yourself. If you're anything like me, I know that you're the kind that never takes suggestions as-is, but instead filter them through your own ideas and knowledge to arrive at something better, more fitting and more elegant.
I can do testing for you, I have real hardware; a backlit gameboy mono, a gameboy color, a Gameboy Advance SP 101 and an EDGB to go with them. I know how to build the source, I'm very good with scripting and I can code and disassemble Z80 (I've been disassembling Master System Sonic 1 and writing my own assembler).
The color hack has been reported to cause damage to hardware in skeetendo. It could have been a mere coincidence, but maybe not. I believe there could be instances where vram accesses occur when the vblank period has already ended, so if there are issues, this may be related to it. I still haven't gotten into that stuff. I just meant testing with an emulator anyway. BGB is as good as it gets.
I must say this offer comes kinda as a surpise right now, but if you would like to offer your help with the testing process, I would of course be open to it. I well aware of your knowledge and experience and I'm sure your help would be very valuable. I still have to clean up some things here and there but if you'd be open to it we can talk privately about this in a near future.
Just a random "I am still working on this" update. The move effects (including battle logic, status effects, field effects and the like), of a total of nearly 300 carefully selected and designed moves are like 75%-80% done and they should be finished in around 6 months. Then I can start working on the general battle UI, animations, held item effects, and AI (in no particular order but currently this is the order I have in mind). Eventually I should get into reworking some things of the overworld engine and start working on a custom storyline and out-of-battle features, as well as data inherent to the gameplay like generic pokemon data and trainer data. I still have not decided if I may try to recruit someone else for help in the animation designs and maybe in the storyline part (this is vague way of essentially referring to anything that doesn't have to do with battling), and, of course, to do some serious testing. This is something I'm considering, but it depends on how things turn out, and, regardless, there is still a long way. Don't ask for or expect a demo until the hack is completely finished though. I once said that it's not going to be possible to finish this in less than 3 years and today it's still the same story to be honest. Realistically, if I keep working on it at this current pace, around 4 years left is a good call.
Alright, I think that's all. It's been half a year since the last bump so I guess it was time for another. Not much to show since what I've been done is not something that you can easly reflect in a picture or even video. But I do still post some vids with misc features/updates from time to time in my <spam>twitter account</spam> if you're really interested.