I only tried it during a known likely bad timing of attempt.

My only days for eating so little were recovery days from a hard workout - and the next day was going to be a good workout too.

So the day at 25% TDEE was not a smart idea and effected the workouts.

Now would actually be the time to try it - my workouts can not be as frequent so I'd actually have some days attempting it.

It's a good way to receive a 22% average weekly deficit, and keep hormones in totally happy state since 5 days eating at maintenance.

But you have to do it right - maintenance is not MFP's estimated daily goal which includes no exercise.

You'd have to have the correct activity level, no deficit, and then either days with exercise correctly eat more - or get an estimate for the week and get average daily level.

Then 25% of that for the 2 non-consecutive days. The 500 & 600 levels is for average sedentary eating levels - not what your days may be.