I can say one thing which is it there is certainly a lot more to homebrew releases than meets the eye, certainly any compliance with modern legislation (which the originals almost certainly didn't have to do) is something that would have never crossed my mind.
He do not know that a repair nor replacement/enhancement for a function internally do not require a weee certification as the device was build before 2006. but if i would add a sdcard or create a new device out of it then i must be compliant which do not work for non rohs component like tia, 6502 etc. As they are completely forbidden on top of new devices (even if weee registered).
I was in contact with curt vendel for example regarding a new Atari 8 bit computer based on ARM cpu but fully compliant with old soft and hardware and after we negotiated the possibilities curt was willing to offer some circuits for cartridge handling. Originally i asked them about atari brand and legacy ownership as atari officially not answered my requests regarding possible brand use or license costs. Finally he was quit busy with his book so i sent over some rare 30 year old Tramiel pictures and articles from my old collector stuff which will be used in the upcoming book. After discussion with my lawyer plan for the computer was stopped because registration fee may kill the economic future of the project specially as the hardcore fans told me that soldering possibility is a must for a next Gen homecomputer (scary... If so the brand do not really care maybe a box with resistors is sufficient for such people

)
I learned during evaluation of different projects (for example a project enhancing snes controllers) that
The european government classified input and output controllers and cartridges as standalone devices so selling, importing always requires to follow the regulation rules. Thats why using original cartridges with new flashed games are ok but writing a brand or add a covers creates a new device out of it then requires registration. Curious, isn't it?
May be thats why thomas is so pissed, his upcoming homebrew game will be a financial suicide run if delivered on cartridge.
offering an external stereo surround mod would not be allowed too without registration for weee and so i ditched the development a while ago even if low hanging fruits. I always talk with my lawyer PRIOR to any project to avoid surprises. For example offering a power supply with own brand or freezer card like a famous atari club does is against european regulations without registration/certification. But as i know they spread this since years so they are already deep in the shit if someone comes along or planned control instance get notice. Due to the power supply branding issue for example i do not relabel the power supply which will be delivered with coleco power connector adapter (as other do).
Today the business is full of traps.