Re: Concerned about hooves. Pics.
I attended one of Pete's clinics in the later part of last year. Pete always says (online as well as in person) that we should strive for the horse to be better or the same in comfort after the trim. The fact that your post says "He has come up mildly lame after his last several trims." is something you could bring up to your trimmer.
Pete's articles to start you off with:
I also see on the pictures a lot of rasp or knife marks on the sole. (Read Pete's sole article carefully)
That straight line across the toe makes me think he is dragging his toe a bit.
Cindy and Glow - Sep 2017, SingaporeCase History: https://ecir.groups.io/g/CaseHistory/files/Cindy%20and%20Glow
ECIR Primary Response