Thank you @floral_uk z.8/9 SW UK: I am going to try it both ways just to satisfy my garden curiosity. Sow some bean seeds between the peas and grow some in pots.

I have successfully transplanted pole beans in pots. Beans do resent having their roots disturbed. I use larger single containers, not small 3 or 4 packs. But they need to be planted before they start growing the vines much.

I would try planting bean seeds in the ground in mid May, right in front of the row of peas, then just cut off the pea plants when they are done without disturbing the soil at all. Plan for this in your garden when you plant the peas. Make a judgement call on the timing of when you plant the beans.

I agree with @floral_uk z.8/9 SW UK's comments. You could start beans as transplants - I use a lot of bean transplants every year - but that should be unnecessary. In warm soil, the beans will sprout quickly... and an early start only matters if you are saving seed. Plant them on the sunny side of the peas, and hopefully the peas are done (and can be cut down) by the time the pole beans send up runners.

Yes. It all depends on one’s climate and one’s specific plot. My springs are slow and cool and the plot slopes east behind a row of tall buildings. Soil isn’t warm enough for beans to germinate until well into May. If I start them inside I can plant them out in April if I give them light protection.

I always transplant bean seedlings. I grow them in plugs, start them inside under lights about 2 weeks or so before planting out (late May-early June).