How big is that incubator?  They are going to grow pretty fast, will a dozen chicks soon outgrow it?
How easy is it to clean that incubator?  Chicks poop a lot, that poop needs to be managed.
If your incubator has a fan, ventilation should be adequate.
You can lower the temperature in the incubator but probably not a lot.  There is some personal preference in this one.  And it is often misunderstood.  As they age chicks can handle lower temperatures.  That does not mean they have to have much lower temperatures, just that they can handle lower temperatures.  Incubation temperatures are real close to overheating them after they grow for a few weeks, right on that border or risk.  They will feather out faster if they are exposed to lower temperatures.  
I keep one area warm enough for them but let the rest of the brooder cool off as it will.  After a few days they spend a lot of time in cooler areas.  I think they are healthier and more robust if they are exposed to some cooler areas.  I don't know how much of that is science and how much personal preference.
I think it will soon get crowded which can lead to behavioral problems.  It is probably be pretty hard to keep clean and dry.  You can certainly try it but I'd want another option handy.  You might need it fairly soon.