The option might already be there, if it is I apologies, but it would be nice if we could save our custom signature in our message preferences tab. This way, when we start a message that signature would already be there at the bottom of the screen and wouldn’t have to be copied in every time we send a PM that would require one.
Same goes for those working mainly in an office their clerking department where 90% of your PMs follow a similar format, you would then be able to just select the format as your signature (Or save it as a preset) to allow these members to save time on sending out a lot of PMs to do their staff jobs.