Quote from: eiger3970 on Today at 01:10:17 AM

Also, is there a way TailOS can automatically not connect to the Internet or have the offline Electrum app in a VM/Container/Qube to keep it offline?

Enable "Offline Mode" in the start menu "Additional Settings" in every session.
However, unplugging to the network is still the recommended solution since some motherboards' UEFI/BIOS can still connect to the internet without the OS.

Quote from: eiger3970 on Today at 01:10:17 AM

Still figuring out how to send from the offline wallet with 1 USB, 1 offline computer -snip-, 1 online computer and 1 online iPhone (no Electrum nor Sparrow app).

To better understand what I've written about it:
Research "PSBT" (Partially Signed Bitcoin Transaction) and you'll be able to tell if a non-Electrum client can be used together with Electrum.

Take note that some tutorials online are outdated and the export/import transaction method will only work in older versions of Electrum.
In your research, make sure that Electrum's version is at least v4.0.1 or above.