Led Lenser P7 DIY Ideas?

I have a Led Lenser P7 which is 5-8 years old and is looking brand new. Not used at all, mainly because of the odd batteries that it uses 4xAAA which are expensive.

The lens has very good TIR optic which does not waste any light and reflects it forwards. I can buy a new light and I have bought, but the build quality is very nice and it is a pity not to use the body.

It is extremely awkward to work with it, and that is why I ask for ideas. There is only one thread on the other forum which sands down the LED tower and changes the emiter on a Led Lenser T7. Nothing on changing the battery type.

I am contemlating something like this:

1. To leave the light as is, and to use it very little, as was the case until now.
2. To somehow make it use 18650, and leave the emitter as is. And have a more practical but still dim light.
3. To somehow make it use 18650, and put XPL emitter, best case scenario - and the ultimate usage case.
4. To leave the expensive AAA bateries and put XHP50 6V, and make god knows what light.
5. Get 10400 lithium batteries, and put XHP35 12V and risk heat and money and runtme, but have the ultimate light.

What would you do?