Tender Spring Swap?

Guys, I’ve read through as many of the spring threads as possible. I was wondering if anyone makes a kit to just replace the rear tender spring, and then possibly use that stock softer tender on the front.

Or just a replacement for the rear tender spring along. I’ve seen the kit from the company that replaces the rear tender AND replaces the front spring, but even that is more than I am looking for…I don’t ride too hard any more and I’m just looking to eliminate sag and keep from the occasional bottom out.

Anyone see anything like that? Or know of a spring that can be used to replace that soft rear by itself?