Hah!
Actually... KTMs had a history of cracking the engine case where the sidestand mounted. And they blamed it on people sitting on the bike with the sidestand down, and similar side stand "abuse"! A close friend had a big warranty battly about it that they eventually covered. And now companies...
That said, you could use the Norden wheelbase spec, and then add half of each tire diameter. And then add an inch for the rear license plate hanger hanging off the back.
There is a comparison chart with the KTM here:
https://adventurebiketroop.com/norden-901/
And apparently the husky and KTM have different wheelbases... so I guess you can't count on using the KTM dimensions.
Well, you could use the longer KTM 890 ADV R maybe?
I quick made an overlay... but these are computer renderings from Husky and KTM. The wheels like up perfectly, but the engine and swingarm locations appear slightly different. I don't trust the renderings...
Is the exact length necessary?
You can probably print a copy and measure the wheel diameter and use that and a little math to calculate the length.
It's also likely similar to the KTM it's based on...
I see some comparisons on the web, but most are not well matched, meaning the bikes have other significant differences.
This writeup is "OK"...
https://dirtbikemagazine.com/ktm-suspension-shootout-pds-vs-linkage/
One of the big differences between the Husqvarna FE vs the KTM EXC-F is that the Husky has the linkage rear suspension and the KTM has the PDS (Progressive Damping System) rear suspension. What do people thing about that? Is the linkage "way better"?