Welcome to the Nexus and congrats for your lifestyle

Mimosa Hostilis (aka Mimosa Tenuiflora) has indeed been used with excellent results for skin treatment, not just cosmetic but also regenerating and healing, since the mayans were around. The popular name for the tree in that aspect is "tepezcohuite". Lots of information can be found online about it. The main difference is the part of the tree used. Whereas for tryptamines extraction you have to go for the root bark, tepezcohuite refers to the tree bark.

As for using it for preparing ointments and creams, you could slowly cook the pieces of tree bark in water until all the goodies are extracted and the solution is well concentrated, reduce the water to a manageable amount, filter and discard the solids and use the extraction as an ingredient for soap making or add it to a base cream. If you have made soaps and ointments with other plant essences, there should be no major difference in the making.