Is it protonated or freebase?

Salts dissolve in blood, but the carrier proteins suspended in blood, which transport lipophilic compounds, should be able to transport freebase too, right?

What form of DMT is it that binds to the receptors?

If it's in salt form, could it be that e.g. tannate salts take longer to fully take effect than say the acetate or fumarate, because the tannate ions are so large and take longer to pass through the membranes?

Different salt forms will have different pharmacokinetic properties. So it makes sense why different salts take longer or slower to take effect. The form a molecule takes will depend on pH of the tissue / liquid its in. The salt form(s) drugs will take will vary depending on what tissue they are in. I don't think the original salt form they were in would be retained once across blood brain barrier or even the intestine. Freebase would absorb more readily across lipid membranes.

I literally Live for discussions like this. Thank you again Nexus/Nexians!

It also makes perfect sense that it changes based on the area of the body.