Advice needed on Maglite builds

Planning some old school Maglite builds and wanted advice / guidance if the way I’m heading is going to safe
Reason for Maglite as they were old builds from CPF days, ROTP, Old Incan setups etc and its about time they got a freshen up

[1]
Host - Mag 2D cut down and bored out to accept 2 x 18650 in parallel (side by side) with custom battery holder + Tailcap switch
LED 4 x Nichia 519A with massive aluminum baseplate / heatsink
Battery - 2 x New 18650 / Same brand, Same capacity
Driver - unsure about, Input here would be greatly appreciated
Reflectors 4 x Reflectors to suit 519a

[2]
Host - Mag 2D
LED - Single CREE XHP70.3 6V mounted on large aluminum heatsink
Battery - 2 x 26650 or 2 32650 running in series
Driver - Convoy FX-30 https://www.aliexpress.com/item/32705084650.html?spm=a2g0o.productlist.main.79.293f2319uCReu8&algo_pvid=df6392f8-ba1d-4c35-97d2-90d6c8b99695&algo_exp_id=df6392f8-ba1d-4c35-97d2-90d6c8b99695-39&pdp_npi=3%40dis!USD!5.54!5.54!!!39.94!!%40210217c716887837006265944d0757!60873852120!sea!AU!0&curPageLogUid=wYZBJL81EhrL
Switch - Custom switch holder in place of original with switch from driver
Reflector - Large metal reflector

Would their be any problems with this setup ? particularly the batteries in series ?

Any advice on both builds would be greatly appreciated
Thanks

Nice to hear ye ole Mags getting some work.

Is the driver of host [1] air wired in the cavity above the switch?

Have you verified that two xx650 fit in host [2]?

Hey dude,
Im working on a maglite 3d 2x26650 xhp70.3 version.
If you want i can send you my current design files and sketches. Please dm me!

#1 Switch is completely gone and and that section is cut off, Switch is inserted into tailcap with driver semi in the heat

#2 I’ve just done some rough measurements and looks like the tailcap might need to be bored out to accept the larger size batteries

Both designs sound right on paper, but devil is in details, you’ll come across those as you build. How is your tail switch as far as current handling? you need one that can handle around 10Amps, judco switches are often used in high current mods.
you do not need to bore out tailcap for 26650, they fit just fine, i used 26650 for ROP light. for 32650 you can not bore out the cap, o ring seat limits how much you can bore out, there aren’t really any 32650 made by reputable manufacturers anyway, they are lotto. even 26650 capacity is not much larger as good brands 21700. i’d stay with 21700

Tailswitch is rated for 10A from aliexpress, using them in both builds
32650 i didn’t even think about the o-ring that’s a good point took a quick measurement and looks like it will burn through

ill check out some 21700 is aus and see what i can come up with