Part of why this TG16 mini is desirable is also the much smaller interest in the TG16 in the retro console space. Legacy systems like the NES, SNES, and Genesis have recently gotten numerous retro re-imaginings. Analogue in particular has been bringing the heat with FPGA-powered repro systems. But we haven't seen the same attention for the TG16, and it's unlikely that we will. There isn't enough attention and not enough stock for legacy games in the second-hand market to warrant it.
The TG16 mini is a decent solution to this. Now if only Konami hires a capable team to handle the emulation, and gets a sizable roster for the game line-up. Most of these retro devices actually have a fairly substantial amount of built-in flash memory, so there should be plenty of room. And having CD-games in the roster from the word go is very encouraging.