Is downloading and building a way to create my own non-variable max-flared set?

[gctwnl]

Turns out InDesign really is a horrible piece of unreliable junk. I have to stay away from variable fonts.

Is downloading and building a way to create my own non-variable max-flared set?

[kenmcd]

There is already a Flare version of the static fonts called CommissionerFlair included in the release from here in the repo.
Here: https://github.com/kosbarts/Commissioner/releases/tag/1.000
So take a look at those - they may already be what you want.

The GF version of the fonts have very limited static fonts.