Hello scitechlive, thanks for taking the time to read my post.
My own research is introspective and does not contain any hard empirical data other than analysis of several measures in different scales, such as amounts of mind-altering substances (or chemicals that can alter neurotransmitter levels to some extent) and time to experiment with things like REM rebound. When experimenting with Galantamine and Choline together, yes it is measured since these supplements come in set capsules of 4mg:200mg (galantamine:choline ratio). I've also experimented with other dream inducing substances such as Silene Capensis (Xhosa) and others I won't elaborate on now.

Regarding the source of this information - well, most supplements that go for the ascetylcholinesterase inhibition route use Galantamine in them as it is proven to be very effective. The most extensive research work comes from Thomas Yuschak, I suggest you read into his work in detail if you're interested in the subject. Since it's a book for advanced dreamers, I took it upon myself in this post to translate his insights along with others' and my own to anyone who is interested in experimenting with high level dreaming in a more accessible way. :D