Preset File name length limits on M:C

So, I’ve just discovered that, via the transfer app, you can set fairly long filenames on the M:C internal filesystem.

This is admittedly not much use on the M:C itself because the screen limits the filename display to 9 chars (and the internal names within the file seem to be limited to 15 chars I think) but you can go beyond both those, which might be useful moving presets back and forth. Eg you could have two presets where the names appear on the M:C as

SY 1 PIANO
SY 2 PIANO

but the actual files (in transfer and on your computer) were more readable as

SY 1 PianoBass
SY 2 PianoMelody

Yes, I’m being very nerdy here. Just organising my presets if you can’t tell. The longest I’ve found a use for is 18 chars.

Question (for elektron, really). What are the limits if I go beyond the rename screen limit (12) or the internal name limit (15). Or should I stick within one of these limits to avoid future problems ?