If insulin resistance is suspected, then adding some HIIT to whatever exercise you are doing might help.
Another suggestion, which I made elsewhere in another context (and which I admittedly haven’t tried myself yet, but plan to) is supplementing with vitamin B5, aka pantothenic acid, in relatively large doses. An alternative is pantethine (more expensive, but smaller doses might work). It is supposed to help us mobilise our own fat stores better, and should help whenever calories are reduced, including fasting.
There is some science behind it, although I’m not sure if the 2 keto dudes would agree with it.
I might ask them about it some time, but perhaps I’ll wait until I’ve tried it myself.
(I’m in a bit of a stall myself, as it happens, but then social / family pressures have meant not being able to adhere to my personally preferred diet as strictly as I might).