Yeah, definitely set up a blowoff if your head space is limited. I've made a few Hefe's with WY3068 (BIAB, single infusion @152°F) and the fermentation was vigorous, to say the least. I pitch around 65-66°F and try to keep the temp no higher than 70-72°F. I assume you are using WLP300, so not sure if the fermentation will be similar, but probably.
Pitching cold and keeping temps in check should keep your esters low, at least in theory. Still, this yeast is usually banana forward, so be prepared. I don't mind the banana, actually I prefer it. What I don't care for is too much clove in the mix. Clove is for Saisons!

I've never used any White Labs Hefe strains, but according to WL, 300 is supposed to be more banana forward and 380 leans more clove.
Good luck. Keep us posted!