Don't bother pre soaking lasagne sheets even if they are the pre soak ones after 35 years in the catering trade and cooking thousands of portions of lasagne I find that the pasta absorbs enough moisture from the sauce's to cook it to perfection 
I understand that in the mass catering industry methods of cooking can be different, but in domestic and resturant catering standards are higher as costs can be absorbed and justified easier.
I have been cooking for at least 55 years, and all the receipes for Lasagna in the domestic arena specify cooking the main meat mix, then cheese sauce separately , bringing them together with the pasta sheets cooked or at least soaked (as I do) in salted boiling water for a time dependant on type, for example fresh pasta sheets for about 5 minutes. Some receipes may specify that you leave the assembled mix to stand for about 6 hours, but us busy mums let the soaked fresh pasta sheets absorb the flavours in the extra cooking of an already hot mix for an additional 10 minutes, or until happy with texture and appearance, which in turn depends on your oven being fan assisted or not.
So what you do in the factory mass catering environment may well be different, as I am sure at least your ovens are operating in a different way than a domestic oven, and the methods used to assemble the lasagna mix in the first place reflect commercial requirements
