While MAOI is required for nn-DMT to function orally, it is not necessary for 4-substituted tryptamines like 4-HO-MET. So yes, for your first quetsion you don't need MAOI. Combining MAOI with it would still drastically change the experience of 4-HO-MET, but thats a different discussion entirely and it doesn't seem highly recommended unless you are very well versed with psychs.
For your second question, I'm not entirely sure what you mean, you'll certainly need a milligram scale to get even a rough idea of how much 4-HO-MET you're taking, you can't eyeball it accurately whatsoever. But yeah, just eat it however you see fit, capsule or not doesn't matter.
Converting to freebase is only desirable if you want to smoke it, and there is very, very little info on smoking 4-HO-MET anyways, I probably wouldn't recommend it. Not to mention I haven't really found any definitive success stories on converting it to freebase from fumarate. So interestingly enough, and I think this warrants a thread of its own, I emailed psychonaut wiki about the dangers of smoking fumarate and here is the reply I got:
"I have previously investigated this topic and concluded that there is unlikely to be any harm from conversion of fumarate into maleic anhydride upon vaporisation and inhalation and this conclusion has been seconded by qualified chemists with whom I have discussed this issue.
Assuming a typical dose of 20mg for most fumarate salt compounds that would be used through vaporisation, for the hemifumarate salt (the most likely form of this salt in this context), 20mg of the compound would include 4.2mg of fumarate, but for simplicity's sake and as a catch-all for cases where a 1:1 ratio may have been used lets say that would be 10mg of fumarate being added. If we assume a 100% conversion rate for all of the fumarate into maleic anhydride (which is extremely unlikely, but that's beside the point for this example) this would yield maleic anhydride levels which are above the safe exposure level for humans; however, maleic anhydride is readily hydrolysed into maleic acid in the presence of water, which is safe to the extent that it's even used as a sour flavouring, and thusly there is by a very large margin sufficient water present in the lungs to hydrolyse 10mg of maleic anhydride so therefore vaporisation of fumarate salts at levels that would be reasonably possible for any of the relevant compounds on PsychonautWiki should be of no concern.
Thank you for your email anyway as this is a somewhat common misconception.
Kind regards,"
So, you can in fact safely smoke the fumarate salt of 4-HO-MET, BUT, freebase would still be optimal, since with fumarate you're likely to accidentally burn it (wasting it) and apparently its not pleasant at all to smoke. As in, its incredibly difficult to properly vaporize fumarate period, but its "safe".
Its a fun substance, I've tried it 3 times at ~10mg, ~15mg and ~20mg. I found going from 15mg to 20mg really kicked up the experience, while shorter lived it felt similar to 2 grams of mushrooms. I imagine the full fledged, intensely psychedelic experience for the average tripper exists around 30mg. My main gripe with this substance is how short lasting it is considering the IMO uncomfortable and drawn out tryptamine come-up. With 20mg it felt I spent 1/3 of the trip on this jangly come-up, 1/3 getting my bearings and actually immersing myself in the trip, and 1/3 coming down pretty rapidly; it felt too short to get a lot out of it, but it was fun while it lasted definitely. As opposed to LSD where the come-up is short and sweet, and then you've got 10+ hours of solid tripping ahead of you...