i have noticed my mimosa hostilis plants to be covered in mushroom-shaped crystal-esque trichromes, some of which have a faint pinkish/reddish hue. which were less prominent (both in quantity and size) on the younger green seedlings, but as the branch/stem turns red, they become more and more blatant (maturing at about the same time and rate as the plant's thorns).

they are very similar to cannabis trichomes in appearance, only noticeably bigger (not terribly huge, but you don't need a jeweler's loop to get a proper glance).

have these been analysed at all?
are they of interest? or just a pretty decoration..

Trichomes are pretty common in several species of Mimosa, including the ubiquitous M. Pudica. They serve a protective function against herbivores, specially insects. I've seen no papers detailing their composition, and according to what we know about concentration of alkaloids in mimosa tissue, I doubt tryptamines end up there in a significant amount... however, it could be tested.

Taking the known case of cannabis, we know trichomes have an optimal maduration stage when they become milky, showing a maximum concentration of THC (a terpenoid), and then the THC oxidizes into CBN as the trichomes become brown in color in the peak maturity stage.

If there was DMT in the trichomes at some moment, as they oxidize and dry out they perhaps would leave detectable amounts of N-oxide in the outer stem bark, and we have no evidence of that.