regarding magi age, I'm going to go with up to gauntlet+15 for Novgorod starting out.
For post-gauntlet advancement, do we use the standard zero lab +3 aura, or do we use the stats for the covenant where the magus actually resides?
use the stats for the covenant. If you want to allocate build points to labs you can customize that as well, though obviously that will require post gauntlet seasons.
That's ok, but it isn't obvious. The improved lab could have been inherited, in fact that looks like the assumption in Cov.
I don't know that it is assumed or not assumed in covenants, but I do assume that covenants in Vovgorod are generally (not universally) young, and customization tends to be very personal even where they are not. It is also worth noting that many improvements do not actually require the magus time- just their presence (aside from ones that are aspects of construction) with the exception being refinement which would require time from the inheriting magus to utilize anyways. The other possible exception are laboratory enchantments, but those realistically should be simply bought as enchanted devices for the covenant and assigned to labs- in Novgorod those could have been found as easily as made. All the seasonal requirements effects for the most part is when you are able to utilize the customization.
The time spent using the lab to learn a spell/enchant an item, you mean? Oh, but that's obvious.,
What I mean is this- lets say you have a lab with BP allocated to 7 points of virtues. You decide to have a major virtue installed right after gauntlet, that takes 2 seasons so you won't be able to make use of that virtue until the 3rd season after gauntlet- it doesn't take any of your time, but it does take time. Then you add a minor virtue, that takes a season, again not any of your time, but time you have to wait for others to finish the work. etc.
OK. Now we understand each other. Thank you.