Figured you talked to Esveld since the topic of matsumurae / palmatum split was brought up towards the end of a recent MrMaple podcast by him.
As far as naming conventions:
- dont mix different languages (chishio improved being the prime example, should be shin chishio), (your name can be combined with any language) ("Arakawa dissected" -> incorrect)
- latin has really fallen out of favor, I think the consensus leans towards reserving it for scientific classification down to species and subspecies, not cultivars. At least in Acer. It can sound like youre granting the tree a rank it hasnt earned, like stolen valour
My 2 cents:
- there are thousands of JM cultivars, if you want to make an impression you have to stop people from scrolling past your cultivar when it pops up in inventory lists. So capitalize on this unique combination of traits you have at hand, as many have suggested. - if you choose a Japanese name, people might recognize the "arakawa" part as rough bark, but youd probably lose the appeal of the dissected aspect for anyone not speaking Japanese, just reading the cultivar name.
Jelle's Lacebark or something in the spirit of that would work, or Rough Bark Lace. English for broadest appeal and feature advertisement.