I dont see anything wrong with it. The unit is defined as a “centimeter cube” which is a non-standard unit so while it is not really a great unit definition, it would still be correct.

I could just randomly divide the scale in equal length sections, say one section is a “squelchon ” and the marker would be 17 squelchons long.

That’s how measurements based upon human appendages came to be ;)

EDIT: of course I mean squelchons and not squenchons (completely different unit) ;)