1) I'm not a doctor.
2) I'm nearly certain that there are no studies on irregular dosing.
It's probably best to allow your body to reach an equilibrium. Keep the dosing regular. If you're switching from one experiment to another in time spans of less than a week you're not really learning anything. Pick a regimen, stick to it for three weeks, then see what happens, then try something else for another three weeks.
It sounds like the issue with you is that the ~70% DHT inhibition is too high. The issue as I told you before is that it's very hard to reduce this number, since 0.05 mg of finasteride behaves very similarly to ~0.50 mg of finasteride. You'd have to do something complicated, like dissolve the pills in a liquid (find out which liquid works for this), and then take like ~0.005 mg per day, for example dissolve 1 mg of finasteride into a 1 litre of water (if water works), then take 5ml of that water per day, which is 1 teaspoon.