I think you’re missing the point about heat.
Could not care less about headers, as you pointed out, you can get salvaged ones just about anywhere, but what your not considering, is damage to your wiring harness, knock sensor switches, and ECU unit.
Most, if not all of these parts are becoming obsolete, and while you would rather ride your 20 year old bike, than be distracted by heat, your modifications could cause serious issues to the wiring.
If that happens, you would probably end up with a 730 pound rolling paperweight.
Last year I had a couple dozen ECU units on hand, now I have none.
Most were used on bikes with these heat modifications to repair the bikes that got damaged.
They are almost completely unobtainable at this point, even from Japan, and IF you could find one, they are selling for over $1k USD.
There are many ways to reduce heat on these bikes, by tuning them correctly, and not cutting, drilling, removing, or wrapping stuff.
Here are a couple pictures after header wrap was removed, and the bike was tuned correctly.
Before with wrap, and poorly tuned, and after the wrap removed, and tuned correctly.
IR heat readings don’t lie.