All you have done this is not a spoon 😯 is add in extra info about the bushes, how does what you have written enable average riders to idetify what kind of bushes they have or determine the best options open to them?
You have 3 main types od bushes available for now
Plenty more are used in suspension, and off the top of my head there are at least a few more used in shock bushes on MTBs, but I’d have to check theyre not just trade names.
There may be tina however those are the most popular bushes in use and therefore the main ones!
Bronze ones that aren’t red are pretty common too.
As stated before the point of saying that the red lined bushes are DP4 is to identify them, all bushes of that kind use a sintered bronze layer on a steel sleave, this enables the PTEE or PTFE + lead or bronze layer to adhere to the bush.
The bottom line is tina, all you have done is tried to discredit what I’m saying in an attempt to be right, I on the other hand have enabled actual riders to idetify different types of bushes available to them.