DruidGhost wrote:i thought that the caapi maybe wouldnt be able to grow large enough in a pot, so i wouldnt be able to harvest enough to get any noticeable amount of MAOI material from it.
That depends on the time you invest... and how large the pot is

If you were thinking about a regular sized pot, say, one foot wide, it would take a long time (at least a couple years under good conditions) to actually harvest bits of stem material sustainably, and probably you'd need to do good pruning work if you wanted to grow to get some day a somewhat thick stem piece - the type they do with bonsais, and vines are not the best type of plant to bonsai easily.
But if you grow, in the meantime you would harvest leaves, eventually stem and twigs when pruning, and you can slowly build a little stash of your own caapi material to use with your smoking blends, or eventually in one very special tea.
Although truth is you would need a lot of time, and a very large plant, to cut off thick stem pieces for repeated use while keeping the plant alive, if you're thinking about harvesting the same type of material that some suppliers offer. We don't have yet an ideal, easy alternative for home sustainable production of harmala alkaloids. The closest in terms of efficiency and time would be Peganum Harmala, which can be tricky to grow in an european flat by a windowsill.
Growing is above all a vital decision, not necessarily a pragmatical one. Growing is a statement. We grow to know the plant, to develop a relationship with it. Some may say - to host the plant spirit. It's nice to look forward to the day you may use the plant as medicine, but as Martin Luther King put it, "Even if I knew that tomorrow the world would go to pieces, I would still plant my apple tree."
"The Menu is Not The Meal." - Alan Watts