Yes, MBD is a serious problem that will cause other very serious complications down the road. I think that he may be slightly showing the first signs of MBD. I believe that if caught early enough, MBD is reversible. But also remember that MBD can be caused from too much calcium as well.
How often are you dusting feeders? If he's eating daily, you only need to dust 2-3 times max every week. Leo's can overdose on D3 (which can cause MBD as well). Make sure the calcium in the tank is pure calcium without D3 and the calcium that you dust your feeders with has D3. Also, make sure both are Phosphorus free as Phosphorus interrupts calcium absorption.
Yes, I agree, however MBD is not reversable. If treated properly you can stop it from progressing and strengthen bones but you can not reverse any damage it has already done.
Well, actually you can, I have seen cases from friend´s animals and nearly not being able to move to going back to abslute normality, MBD is reversible
The bones can become strong again yes and they can live a happy normal life but any deformed bones caused by MDB can not go back to normal.