I've grown these several times and they do self seed but, in my experience, they almost always revert to the deep pink of the wild foxglove. I'm sure someone else will give you more helpful advice though.

yes they are good for pollinators and they usually produce seed. But not many are stable ie giving you similar characteristics to the parent. You may find that you get some pretty variations and it also depends which others you have to pollinate them.

Oh good! That sounds interesting. I like the idea of surprise colour combinations and if they revert to the wild foxglove, that's fine too! Thank you both.

I have grown yellow spear from seed last year so they will flower this year. would you like a plant to try it? if yes send me a pm with your address :o)

You're really kind, SBG. I'll do that.