I would respond by asking: why would you want to do that? The stock spacers seem fine to me, nice, compact, integrated with the axle, perfect fit on the swingarm... what's wrong with them?
Taking the risk of digressing... It's not a matter of atitude, honestly... Your first reply was a bit "agressive" and not asked for (sorry, in advance, if i miss understood it) , as it was the "first" paragraph of you second reply (I'm trying my Best not to digress... 🤔). But The second paragraph of your Last reply, now that's the "money shot"! That's exactly what i was looking for, an answer with technical info and knowlege that i don't have, not even close. But once again, as i did on that 1st request for that service manual, THANK YOU VERY MUCH FOR THE SHARE!I actually didn't make any comment - positive or negative - about the LighTech adjusters, I was simply asking why were you looking to replace the stock ones as they seem to work quite well. And since it's you who is coming here for help - just a week ago you asked for the Service Manual and I gave you the link - you might want to reconsider your attitude... even if you don't get the answer you want, remember that we're all trying to help when we can, how we can, in our free time.
Anyways, back to the main subject: LighTech chain adjusters don't seem to be available for the 899. I do not have direct experience with them (so I'm giving you a personal opinion) but even if you find a model that fits precisely on the swingarm, I doubt you would be able to make it work because on the 899 the rear axle is threaded into the right-side adjuster block (see photo I posted above).