Thank you for the detailed report.
For a pre-dose I usually take just 100 mg harmalas (the harmine-harmaline extract that comes out of syrian rue as is.) I won't say other doses are worse or better, I just haven't experimented with other pre-dose enough to compare. As you know we all differ and must find our own sweet spots.
I'm not surprised that 30 mg deems take you that far, not hyperspace though but still far enough for a firm soul treat. For me it can take me also harder than expected, but also very dim so it depends on the occasion. But same goes for 75 mg if I'm honest, it can be easy ride or deeper, all depending.
You said that the harmalas kept working long after the dmt died, but if you look closer then this long feeling is different compared to harmalas alone. Imho that long harmala feeling is 'enriched' and of a higher (ahum) order because there was dmt before. I love that state.
Happy trials