The way to keep them from bolting is to deadhead them immediately after they finish flowering. I don't have them anymore (too much work) but when I did, if they got leggy like that, I cut them off, rooted the tops (easy) and replanted.

I'm not sure that immediate deadheading will solve the problem. I grow most of my heucheras for the foliage only - I dislike the rather insipid flowers and cut them off as soon as they appear. But that doesn't stop the woody crown extensions. Like Sara, I just cut them off. The original plant will regenerate from the cuts and if you root the cut off portions as well, you will increase your supply of the plant.

As an aside, I don't find most heuchera hybrids to be very long lived....3-5 years is about the best one can expect.

They bolt a lot faster if you don't deadhead. But I gave up on them long ago due to the points you made - too much fussing and not long-lived. I had a glorious stand of 'Old La Rochette' at one point, scattered through a bed with 'Claire Matin' roses, which have exactly the same flower color. It was stunning. But I grew old keeping up those blasted Heuchera! They were the only ones that I have ever seen where the flowers were better than the foliage. Otherwise I'm with you, the flowers are an annoyance.

LOL!! The only ones I have ever let bloom freely are the red flowered varieties of Heuchera sanguinea, like 'Firefly'. But those come with plain green leaves (boring), are becoming increasingly difficult to obtain (compared to the hybrids) and I have plenty of other hummingbird attracting flowers, so no more of those either.

Since I grow these primarily for that evergreen foliage color and usually in mixed containers, the flowers are really unnecessary. I do transition them into the garden when I redo the containers, though.