To be honest, I never thought to start peas indoors. Probably because I was always told to start them outdoors around St. Patrick’s Day (when I lived in Delaware, now I do it earlier) also, I plant a lot of them.
It takes about a week or so for them to germinate indoors. You can probably save about two weeks at least.
I start them in peat pots, though. I don’t think that they tend to transplant very well otherwise and the peat pots have less disturbance of the roots.
The advantage to starting them indoors that is that otherwise, the plants are just starting to produce as the hot weather sets in and don’t do so well.
Anyway, that works for us since it doesn’t really warm up until mid April at the earliest, and usually later, here in NY. Stuff like tomatoes can’t go in until after a the middle of May if the long range forecast looks good. Otherwise, it’s Memorial Day.