Question about Egg Hatching

Last night I hatched nine 5ks at once using a lucky egg and want to do something similar today. The only problem is that I now have two 5ks and seven 2ks to incubate, and I'm wondering what I should do to get the most XP for hatching.

They say you should only use the permanent incubator on 2ks, but if I want them all to hatch simultaneously I'll need to use the temporary ones. Should I ignore this guideline in favor of XP, or just hatch the 2ks one at a time?