Thanks for the reply Brad. Looking back at the effects routing diagram I see that there is no way to 'insert' effects.
I do wish there were more options for sending a combination of banks to the effects though. I can't imagine there would be any hardware limitation to sending banks 1 and 2 (or 2&4, or 1,2&3 etc.) to FX. You'd have to cycle through 14 options with step key 15 when assigning FX target, but it seems like it would be possible through a firmware update.
So far I haven't got the 'Current Bank' FX target to work. Would be nice to put a LPF sweep on a pad from Bank 2, then switch to Bank 1 to sweep a lead without changing the pad. Maybe I'm doing it wrong...