Mods/upgrades for Vector POB 35W HID

Going old school on this one. I haven’t fired up my POB in years. The battery is prob junk.

Any upgrades to the HID system? I know people used to do a bulb swap from that ugly included tint.

Any lithium or other upgraded batteries? I’d prefer using the plug charger system even if I have to incorporate a new charger. Or I can run 18650 and charge externally.

Back in the day it was a monster, I believe 3500 lumens and tons of throw. Now LEDs have caught up in terms of output and possibly throw. Would I be better off throwing an XHP-70.2 in it? How to heatsink.

Any ideas or suggestions?

Thanks