I'm in the same boat. 34k is probably too early--Toyota honestly thinks it won't blow until after 150k. OTOH a pan drop would ensure it, and you wouldn't need to do a full fluid exchange.
I'm not familar with your setup. I want to say though on that 5spd it should hold more like a couple of quarts in the pan... On my Tundra I have an external transmission cooler; I'd think you'd have one too. For me, I can drain the pan, then fill it up, there is a large bolt on the transmission side with which you can either use a transfer pump or instead snake tubing up into the engine bay and then use a funnel to refill. Then I can pop a cooler line, and start the engine, so as to do a full exchange (pump out 4qt, stop, fill up with 4qt).
I'm guessing you can do similar. Toyota sealed transmissions need to be at the proper temp, but I think you can short a couple pins on the OBDII connector and it will flash the ATF high temp warning light at the right time.
I'm guessing you can find a writeup on one of the 4Runner sites. I'm guessing it's very similar to the Tacoma writeup.