I think this greatly shows that the Lepton isn't horrible. But having a proper lens that is focussed correctly and not blurring the image really badly and using MSX as a crutch, you get somewhat useable image due to the third party app.
When I started out in 2016 the shitty 80x60 Lepton and it's default lens was all that I had, but the app made a big difference. Sadly I wasn't skilled enough back than to do any computational stuff with the raw data, but it's something I want to revisit. I now have the 160x120 Lepton and the same horrible default lens, so there is a chance I might look into exiftool again.
I originally found out that TPL was doing Lepton based weapon sights (and also firefighting monoculars), but they had 30hz versions and better lenses. They did quote me like 250$ for one of those lenses and that was really excessive. It would also require some serious modifications to my phone back that to get it working. And knowing how I am struggling for like 3 years now to built a custom camera lens mount for my large cores and lenses - it was a good thing to avoid.
I can't find the old thread right now as I should be asleep already, but when Bill sold me the 18mm f/0.7 prototype lens I had a lot of fun to figure out how to convert it into a attachment for the phone and work with the given Lepton lens assembly. I sadly broke one of the three elements, but it was a big success for my modeling, printing and thermal endeavours. Of the many images I took, a Zine has been made which is still not printed and distributed (somewhat pandemic related, but once I figure this out towards the end of the year, I will make a post on this forum and send some out). Main point being, I also got a 4.5mm lens from bill that supposedly covers about a 12mm image circle for the 160x120 sensors that were like 45μm pitch. Given that the old Lepton I have is much smaller area, it should really fit between some of the shots above. And it would be a great project to try. My old phone is just laying about and the Lepton could be recovered and put onto one of those breakout boards. I definitely have the time and really want to do such a project as EE experience and I am also excited for working on the coding side - but I doubt I would take the time, given that I have much larger cores and lenses laying around to do the same project with: stacking for resolution, noise, focus and stiching panoramas.
There is lots of threads from the last 5 years that could be linked here including lens mods other people made.