I understand that you want people to upgrade from Hexprog I to Hexprog II, and of course, selling the newer hardware is part of the business. However, I think it would be fair to offer a VFI adapter for Hexprog I as well.
Hexprog I still works perfectly fine to this day, but after upgrading to Hexprog II, the original unit becomes almost useless. It doesn’t really make sense to keep a complete programmer just for CAS and FRM functions. As an IC programmer, its EEPROM chip support is also very limited, and there are no key programming functions available.
Does Hexprog I really not have any available output that could be used to control/switch the power supply for the VFI adapter? Couldn’t an external power supply be used for the adapter, together with the same grey boot pin connection?
A VFI adapter for Hexprog I would give the older hardware a useful second life instead of turning a perfectly functional device into something with very limited value.