Your suggestion is actually very smart.
There might actually be a way. Even if it on the phone itself.
For example, you can point a VPN to a local “Hardware Wallet” on the network that signs your events for you.
Then gives it back to the app.
Discussion
i'm not a hacker but i can usually see obvious vulnerabilities in a protocol
i expect if you guys make an app that lets you do this that before the end of the year crapple will ban it but hey, i've seen this shitshow for the last 39 years or so over and over again be hostile to the user so yeah
but i hope i get a crack opened in the wall at least for a while