Hi Between rides, here’s the tailcap fix for the old JM07.
First remove the inner tailcap:
Then add some washers, I’ve added 5 thin washers in total about 1.5mm in height:
That should hopefully solve your problem and keep the battery in nice and tight. I haven’t had connection issues since. There’ll be a small gap between the tube and tailcap, but the Oring is still well and truly covered so there won’t be any water proofing issues.
Thanks, JR, that's just what I was looking for. I'll pick some up at the Ace Hardware and try that out this weekend.
Happy Trails.
So after some further testing, current measurements as follows off a fully charged King Kong ICR 26650.
1 cell : 2.38A
2 cells: 1.25A (2.5A)
Trustfire 26650:
1 cell: 2.2A
2 cells: 1.25A (2.5A)
Looks like it regulates and performs better in the 2 cell format.
Here’s a runtime test comparison with the old pro in single cell format.
Tailcap readings every 15mins with 5min cooldown with a King Kong 26650ICR:
Voltage:
I got 2.5 hours runtime on the new JM07 on a different test before voltage warning kicked in, the old JM07 2hrs and 6mins.
A win on performance for the old Pro in single cell format, unless you want more runtime. Of course the new JM07 can be run with an extension tube with 2 cells.
OP updated.
Wow, great information JR. Looks like their both winners. Hey thanks for posting the pics on the tailcap fix. I went hunting for ultrathin washers last night, finally had to settle for a plain old zinc coated washer, but that worked fine. I'm going to keep looking. It seems to have fixed it (at least the battery slop is gone), but I won't know for sure until next ride. No mode change with violent shakes anyway. 
Hey no worries Betweenrides. I was a complete newb when I first started getting tailcap issues and had to return it 3 times to my dealer before I worked out what the problem was. 
Any kind of washer will fix as long as you lift the inner tailcap by about 1.5mm, the original design just doesn’t press the battery against the driver spring hard enough. Hopefully that settles the problem.
Just found another cool perk with the new Pro after removing the bezel, the wide angle magicshine lense fit’s almost perfect:
Moves around a little so not quite waterproof, nothing a round of silicon rubber around the edges couldn’t fix.
About one month on I’m still loving this light, fit and finish can’t be beat IMO and it’s one of those lights you can’t help but keep picking up and molesting, before wiping it down after putting your greasy mits all over it. 2 weeks ago I got my first solar force hosts, 2 L2T’s and 1 L2M, and whilst they briefly stole the show I found myself going back to and admiring the new JM07.
I’ve got a real shadow fix now, so next I’m getting the VG10 and VG20 as they look great and also look like easy mod lights.
I’ll be getting one, NW, but wonder if it comes w/ extension tube? It’s ugly, but could be good for a long trip or something…
What do these do to the beam?
Int’l outdoors sells it with the ext tube, I’m sure most sellers would, might pay to check with them before ordering. I thought it looked a little funny before purchasing, trust me once you have it your opinion will change, it’s a real beaut in real life.
Cullen the wide angle lense changes the beam profile to one that’s very similar to an automobile light, it completely flattens and widens the hotspot and spill. Handy if you need a floody light for nightriding, I’ll try and add some beam shots later.
Thanks fishinfool, jacktheclipper, Pavithra_uk 
Thanks for the review! 
Anyone here do any mods on it?
1) Higher amps
2) SST-90 swap
3) mode memory
4) mode sequence change to: very low, low, medium, high
thanks
I’m actually the process of modding it now,I’ll add a new post shortly.
Looking foward to it. Thanks.
JR…An impressive array…is that really a MB or a light-bar transportation vehicle?
How well do those clips hold on to the wider bodies on the trail?
Or even a pot-hole on the road?
I’m thinking of adding a stretchy bandage type as a fail-safe.
Thread here, not yet quite sure what to do with it.
At night it might as well be a UFO where I’m currently at. 8)
Those mounts work very well, haven’t had any lights fall off them and they seem very secure, although I only do light trails or pot holed roads at night. As you mentioned for a fail safe you can get rubber o-rings, long ones, that can hook from the flashlight head to tail and under the bars, although I haven’t bothered as they seem secure. The mounts slide down if you don’t screw the screws very, very tightly, or a bit of added rubber around the bars does the trick.
thanks for the link. hope you succeed - you did a great job in disassembly.