There are two cashu wallet apps in the app store but no mint.
Is there a reason why a cashu mint, using the lighting node in our Umbrel, hasn’t been released yet?
Given that a mint is a custodial solution, running one comes with all the responsibilities and obligations of running a centralized solution for accepting third-party deposits. Respectfully, Umbrel is fantastic, but it seems unfit for that purpose.
Mints should have mature operational configurations - continuous availability architecture, disaster recovery plan, robust security posture, etc. Running a mint on a standalone Umbrel node is an antipattern.
No different than providing use of the lightning node via BTCPayServer or LNBits.
You are overthinking the complexity.
Also, ANYONE can currently set up a mint via the command line. It would be nice to have it integrated into an app store for easier install/upgrade.
Everything you listed is 10,000 times worse than leaving sats on an exchange - not really something that should promoted, IMHO. You are right that it is easy to run a mint - just check out the awesome-cashu GitHub: GitHub - cashubtc/awesome-cashu: A curated, collaborative list of awesome Cashu resources
You certainly have an opinion.
HFSP. 
bump
Appreciate the team at Umbrel for adding Fedimint to the app store. Didn’t realize this hit early this month.