The OEM spring on the KKE rear shock on the Templar is 350 lbs per inch. It is the stiffest spring available from KKE for that shock. I contacted KKE Racing
(2260 S. Haven Ave Unit B, Ontario California 91761, United States), but their primary motorcycle product for North America is wheels, not shocks. But they can get you a replacement shock.
KKE model number is MA40B03
He quoted me $169 plus $80 shipping
Ya I know, shipping is ridiculous, but these are OEM supplied by KKE, manufactured in China for motorcycle builders like Zuumav, Kamax, etc.
To figure out what spring could replace it (not KKE racing), measure the mounted length from end to end first, Then you can remove the shock and measure the internal diameter on the mounting ends. You can measure the length uncompressed when you have it out if you want to. Overall spring length is kind of important. It might be hard to find much stiffer spring though.
FYI- I compressed the shock by more than one inch and it was STIFF!!!
Chances are, all you really need to do is compress the preload.
Look at posts 12 through 14 in this thread for a how to on preload adjustment:
https://www.chinariders.net/showthread.php?t=31860
Alternatively, The bolt diameter is 10mm (upper and lower rear shock mounts) and bushing length (22mm for the upper, and I think the lower one is identical - you can measure it). Find a shock with the same mounting bolt size, ~ same length or shorter if you want to lower it (1" shorter creates ~3" to 3-1/2" lowering). The only possible issue is the side mounted ballonet has to be at a slight angle to fit. Just get one without a ballonet to avoid that problem!.
Here are some specs I sent to KKE racing:
Some specifications:
-460mm distance from top to bottom mounting positions (center to center of mounting holes)
-10mm bolts top and bottom (mounting holes)
-22mm wide upper mount bushing
-350lbs/inch spring
-rebound adjustment is at the base of the cylinder on the lower mount
-compression adjustment is on the top of the ballonet