Hi,
DS5 has an OT and is working on HWT with them. His school is implementing it also to some degree and also using their own methods. I think with the HWT he really will learn to write! It's a bit slow though in that they've only covered maybe 6 uppercase letters so far.
For right now DH and I have chosen not to stress handwritng at all for worksheets (we are doing some afterschooling as his K is mostly play and what isn't play is inappropriately levelled (except for the writing portion)).
We got a set of letter and number stamps, suddenly DS has a much happier attitude about approaching the work. Also I will let him make worksheets into a matching with lines versus write out an answer. I feel justified in letting him out of some of it because he truly is working on the handwriting in other ways, every time he looks at a worksheet he does not need to feel like a failure. Drawing a line from one place to another is hard enough for him that it's still good practice on his fine motor skills.
For homework from schools, I've seen on here where parents will send in worksheets the child has done at home that are in the same subject but appropriately levelled. Ie instead of a circle the Hs page, send back a word search puzzle they've done instead with a note that you'll be providing differentiated homework if it something you know they've mastered.