But do you have statements which causes Exclusive Locks? Ignoring them in OLTP won't make your life any easier.
(Keeping avoiding to get into 'recovery conflict' as your sole goal) If you decide to run pg_dump from master, it would block such statements which have Exclusive locking. This would cause delays, deadlocks, livelocks etc and it might take a while for your before you can figure out what is going on.
I would say try to find out who is and why is someone creating Exclusive locks.
Yeah! The pg_dump was already running on the master... it's been running for months.. I just wanted to change now to use the slave, but it seems I can't right?
Exclusive locking - I probably have statements that causes this. Is there any way I could "track" them?