Ever used Revolut? They let you change the PIN from the app, but the experience is horrible.
You change the PIN in the app, then you got to a EMV machine. If it’s online then the new PIN fails the first time you use it. If it’s offline then the new PIN will always fail.
But the end result is you’re not sure what you PIN is, and getting it wrong too many times makes many things unhappy 
. When I tried it with my Revolut card I ended up using an ATM (the only surefire way for the PIN to update) anyway because I didn’t want to risk my card getting blocked/disabled (and I couldn’t remember my old PIN).
I asked @tom on Thursday the same question and he said that Mondo won’t support it for all of the above reasons.