The indole smell is really evident for me when it does come about. One of my favorite smells is when im brewing mimosa on the stove for long periods of time. Im pretty certain that years after working with DMT, whenever id start brewing mimosa on the stove and let the steam/smell get thick in the house - I start to have a mild alteration of effects - increased heart rate, lightness of body, visual acuity heightened slightly though very noticeable; an expansiveness of thought, color saturation, etc.
The memories associated with these times I smell DMT strongly; it's impossible to describe for me. The memories come around sometimes; but once in awhile - they'll come in full swing. If I go to close my eyes and get a big whiff of either straight DMT, vaped DMT, or mimosa/etc on the stove - im flooded with intense memories - specifically memories from some of my deepest, most intense DMT experiences. These memories then take shape in bits and pieces though never fully; kind of like how a dream starts to piece itself together if you hold your awareness at night while you drift off into the pre dream state. Literally, pieces of Hyperspace start to come together during these moments, but they are sporadic and short and never fully form. It's essentially 'memories made to reality' from behind the closed eyes.
Personally, I think Hyperspace is right there, behind the eyes, always present - all the time; although I think smell can/will trigger a cascade of effects, especially with eyes closed. Also I think the intensity of the memories/visions after smelling DMT are in some way related with how deep one's gone. All very interesting.