Used to grow pea seed for years.   They're not hard to plant but yes do have to put in nitrogen fixing bacteria when filling the drill. We always swathed them soon as the peas were hard, (like hard dough stage in wheat) used lifters on the swather, and had a drum roller on the rear end of the swather.

At the stage we swathed, the vines were still green so we could really compress the rows to prevent blowing in the wind as the vines dried.

If you've got a cylinder type combine,, the slower the cylinder the better to prevent cracking. long as the 'mass' is brown and dry it takes nothing to shell out the peas. Get all the wind/air possible in the machine.

I'm thinking about raising peas again. Wheat sure isn't worth the effort..