I also have Morton's. Have had it for 10 yrs.
Cycling and backpacking agitate it the most.
So does sleeping with socks on my feet, the socks actually squeezed the joints together, causing agitation.

I did have surgery, it came back worse because of scar tissue.

All of my footwear have homemade metatarsal arch supports constructed of molefoam and duct tape.
I have modified in this way...
4pr of ski boots.
2pr of cycling shoes.
Pack boots.
Hiking boots.

My molefoam solution has elimated Morton's pain from my activities.

I had a custom orthotic made (~$350) which was heavy, did not fit in all of my footwear, and was destroyed in 2 months.

My hiking boots are full shank and very stiff.
I prefer stiffer, more supportive soles in my footwear, less flexing of the joints.

Sorry, I know my post is a stream of consciousness about Morton's. If you have more direct questions, let me know.