I would like to recommend to NOT truncate the Message length on Notifications.
The incomming texts are already limited by what can be send and the Contact-names/Channel-names are also limited.
So they wont be more than approximately 185 chars.

I write this, because i like to watch the messages coming in an my smartwatch
(Companion -> App -> Notification -> Gadgetbridge -> Smartwatch)

Sincerely Eric