Isn't a "chiptune" specifically not using sample snippets (like Amiga MODs) but synthesized audio by a specialized audio chip (like a SID or AY) - and thus the name chiptune?
I'm no retro-audio afficionado, but that's what I would think of when when hearing the term (of course there's a grey area like the Namco WSG audio chip which uses small wavetables usually stored in ROM with 32 4-bit samples each).
In the 90s at least, chip music for the SID was mostly called "SID tunes".
People didn't care about authenticity of real chips vs. chip-style tracker music until fast Internet and large disks became common. People stopped caring about small file sizes, and started making chip-style music using DAWs and releasing it as MP3s. There was backlash against this, and people began to think that only music made with hardware chips was authentic.
I believe tracker chiptunes were collateral damage in the rejection of MP3 chip-style music, because there's no way to to clearly define if tracker chiptunes are real chiptunes or not. Lots of tracker chiptunes use short percussion samples in addition to the looped single-cycle waveforms. When there was a culture of keeping file sizes small, this was accepted without question. When large file sizes forced people to start thinking about what counted as real chiptunes, this element of subjectivity became a problem. How long a sample is too long? With music for sound chips it's easy to test if it works on the real hardware. There's no equivalent test for tracker chiptunes. It's easiest to rename tracker chiptunes to "chip style", and use "chiptune" to mean hardware chips only.
The meaning of chiptune has been overloaded since at least 1994 when I heard it both for what you say, simple Amiga MODs and for C64 and Spectrum tunes. The first term was used for MOD compos.
It uses emulated audio chips from Mame emulator. Some audio chip emulators are pretty damn good, the best thing you can get without having actual analog hardware in the loop.
Looks like it only support SID, AY, FM, etc. tunes. Just chiptunes missing.
Don't take me wrong, still interesting. But should really get terminology straight.