If you have a TG16, why not just use a passive converter?
Because a region mod is cheaper and far more reliable than a converter?
How is opening up your console, breaking and soldering up a bunch of connections "more reliable" than sliding in something HuCard-shaped into the HuCard slot? I can't even fathom the logic. (The cheaper part is undeniable, though.)
I definitely agree with this sentiment. As I said before, I dislike making any changes internally to a game console, including the Turbografx-16. I like it the way the system was originally designed. It's a Purist way of thinking. Plus, there is always a risk of damaging your system no matter how skilled you are. I know this because I installed modchips for people back in the day for PS1, Dreamcast, Xbox, and PS2. And as time goes by, a short in the solder connection(s) can also cause the console to just stop working altogether.
A converter acts as an external source, and if it breaks down, just go buy another replacement. I believe there will always be somebody who will be making a converter somewhere in the world. They don't make Turbografx-16 or PC Engines anymore. The systems will get harder and harder to find as time goes by due to people holding on to them and heavily broken consoles that get thrown in the trash, especially when the TG-16 was less known. Therefore, a shortage is more likely than say the Atari 2600 or NES.
You ask, "What if somebody makes a clone TG-16?" I say, so what? A clone system is not a TG-16 in my book. It wasn't made by NEC and will not have the same quality and antiquity. Have you ever heard of Clone systems of NES, SNES , and Sega Genesis that had the EXACT same video/audio processing as the real thing? It's always this or that...the audio is terrible. The video is blurry. The plastic is cheap. It can't play certain games. etc., etc.