-snip- And I was able to verify this one using Trezor... but it doesn't seem to verify on Electrum or Mycelium? 
-snip-
-snip--snip- Not sure what's going on, and how to verify the next sign messages if created with trezor. Is it needs another trezor to verify the message?
Because Trezor uses BIP 137, and there are no standards in bitcoin signatures, each wallet can have a different standard.Some references that I took.
Last night BIP 137 was merged into the Bitcoin BIPs repository. You can see it here. This BIP documents a standard signature format used in the field today. It was actually first implemented (from what we can tell) by Trezor. Unfortunately, there are no standards used for signatures in Bitcoin and most vendors are doing it differently and support varies widely.
BIP 137 which could be standard for sign message with SegWit address isn't adopted by anyone and each wallet have different standard.
So if you sign a message with Trezor web interface, you also must verify it with same application. This applies for all wallet, unless 2 or more wallet use same standard. -snip-
So if you sign a message with Trezor web interface, you also must verify it with same application. This applies for all wallet, unless 2 or more wallet use same standard. -snip-
-snip-
Done,
