When the sounds were made, we were asked to keep them short (but not too short since they play every 8 TICS), don't think we ever payed attention to them in-game enough without music until recently to notice the ticking. This was nearly 8 years ago after all.
There isn't a good way to loop these sounds properly via editing though I don't think the casual player would notice an FM sound not looping 100% perfectly, you'd have to have extra sensitive ears to notice this discrepancy.
Maybe if the sound engine were to support looping SFX of any arbitrary size, this could be achieved without any file editing.
Unfortunately we don't have the 1:1 working files for them anymore since we were asked to make changes to sounds but then a previous iteration was used instead. I'm sure if we were to check the SMPS file (yes, they were made in a Sonic 1 ROM hack and recorded via KEGA Fusion) we might be able to find some leftover patches or sequences.
There are still leftovers of it in Pantufa : Extended Edition and the XMAS demo of Gatoslip, so if someone's dedicated enough, it would be fun to see these recreated in Furnace.
EDIT : I should specify that the "we" here refers to our plural system, not as in KartKrew and "me", realized some may misinterpret that so we're clarifying it.
