Ill let you know first that I haven't done freebase, so anything I say is based entirely on Changa, and is based on my limited experience.

It's also hard to match my dosages with what you describe, as the feeling on the exhale and popping into hyperspace is such a small part of the trip.

I am also a very big guy. Around 6"1 and about 370 pounds. I'm not sure if that affects the effectiveness of a dose though.

Both of these examples have the same feeling on exhale, with the second example taking me to hyperspace.

My first dose was 0.07g of Changa, and that was just a nice warm buzz, very limited visual distortions, and basic geometrics. Nice chilled afterglow, lots of love in the air.

My second dose was somewhere between 0.15 and 0.2g, and that launched me very rapidly. I felt a rush when I inhaled, and within 5 seconds, my body was overtaken by an indescribable force that utterly dissolved and shattered my sense of self. Extremely strong visual distortions, I had to avoid them to break away from reality. And an afterglow that can only be described as godly.

For me, I'd say hyperspace would be at around the 0.15 to 0.2g mark. But again, that's with Changa.

For all intensive purposes though, how I dose is probably vastly different to what will give others a positive experience, so if you're looking to learn what dose works for you, I'd recommend working your way up from what last dose you felt comfortable with. That't my approach anyway.

Hope that helps!