Diacritics being defined more than once in different spots

[TealUmbrella]

If I were to have a setup such as

Feature +aspirated
Feature +preaspirated

Diacritic ʰ (floating) [+aspirated]
Diacritic ʰ (before) [+preaspirated]

It would give me the error "The diacritic "ʰ" is defined more than once," even though it's put in a different place. I'd like to add preaspiration, but I can only do it using a different Unicode character.

[def-gthill]

This would lead to ambiguous parsing. Does apʰpa contain an aspirated stop followed by a plain stop, or a plain stop followed by a preaspirated stop?

As you say, please use a different Unicode character if you want both aspiration and preaspiration.