I *always* start them indoors. Why? Because I have cutworms, and if I seed them outside, I'm never quite sure exactly where they'll come up, so I don't know where to put protective collars. To the extent they grow fast, no problem. Just plant them out fast, before they get rootbound. I've never understood these warnings about root disruption. My experience is that those warnings don't make a lot of sense. If you plant in paper cups, at 70F, you'll be planting out in a week to ten days.

I guess letting them grow large in bigger pots, and planting them out as soon as frost danger is past will speed things up a bit, but they grow so fast, it's not going to make a big difference.

I agree, if you transplant before roots are to big it seems impossible to have an issue. I had cutworm knock off my cuc's in my front garden for the first time last year. I will be ready for them this year!