I am trying to find the best trail running shoes that can handle trips on the JMT. I have tried to several good quality brands such as the Solomon high top X Ultra last season along with heavy weight hiking Darn Tough socks but unfortunately got bad blisters on back of ankles and find hiking boots to be a little too hard on the foot beds. I broke in the boots several times before trip and had no bunching in socks. They seemed Ok until I did the real hike, after day 2 blisters! Wonder if there's a comfortable cushioned yet sturdy enough low cut shoe out there that can handle the rocky Sierras and not cause blisters?
People hike the JMT in trail runners. It is generally a well graded and well maintained trail. You may want microspikes over the passes since there can be snow particular on the north sides and it will be icy early in the day. Probably much less snow this year.
Examples are Altra Lone Peaks (zero drop so you need to be comfortable with that since it stretches the Achilles. The 4.0's have nice heal padding. I find them a bit squishy. I replaces the insoles with keen utilities for a bit more shape. Don't know about the current version. Probably too wide for you), Brooks Cascadia (I have used these in the past and have a new pair to try. They are a bit less padded ), Hoka Speed Goats (I have heard good thing) but there are others. I would get fitted at a good running store although REI carry a limited selection and may have a better return policy.
You also might try taping up your ankles with Luco tape or similar before you start.
Darn tough socks work for me but you might try a liner sock.
I'm using my hoka stinson atr5's again this year on the JMT. NOBO from Kearsarge Pass, 2 Aug.
Best shoe I've ever backpacked in. Rugged, extremely cushioned comfort.
I switched to Trail runners from hiking boots a couple of years ago. I even used them for carrying a heavy backpack.
At first I bought expensive trail runners. I walk off trail a lot and I found that they were not able to take the abuse. I was going through two pairs a year, sometimes 3.
Now I just go to Big 5 and find something on sale. I could spend $100 plus each on two pairs of shoes a year, or I could spend $25 to $30 a pair and get three pairs a year.
I don't feel too bad about being a heavy consumer in this area as in many other areas I am not a heavy consumer.
I have used Topo Athletic Terraventure for long JMT mileage. Never a blister. They have wide toe box. Always size up at least one size to normal to allow for swelling and expansion. They dry quickly and easily last JMT. I have not had a pair of "hiking boots" in a decade! Do not go waterproof as they will not dry out and you WILL get wet in water crossing. Watch pricing and you can get for around $100