Clip envelopes/fades/mutes,... move with the clip. I use these a lot.
I rarely use track envelopes/automation.
Bus envelopes: since I aggregate tracks to buses (guitar1,2, guitar effects, guitars all, purc all, instruments all, vocals bk grnd, vocals main, vocals all,...) I use bus envelopes/automation for all the stuff not done with clip envelopes.
To the OP: instead of using track automation, send all the tracks to a bus, add an output envelope, fade to taste. This way if you need to change the fade you only have to change ONE envelope.