well depending on your "smoking" or "vaping " tool. I used GVG and torch lighter and made eLeaf ( with mullein as leaf base).
Cutting agent sounds like drug business.
I'd rather call that a diluting agent.
I do'nt know but there is maybe some inert crystal like substance you could use for that.
So yeh use th plants like mullein and any fancy smelling too like lavender and white sage for taste or mint.
But avoid making genuine changa as said above harmalas might make this even more unpredictable and potentially even more dangerous.
5 MeO DMT seem to have less safety records than plain n,n DMT so everyone should record its dosage and start low to increase by the mg carefully. Don't jump fomr 5mg to 20mg for exemple.
Smell like tea n,n spirit !
Toke the toke, and walk the walk !