Yep you got it :)

To some extent I to am learning about this program also, though possibly from a different perspective. When someone posts an "aggh my program is not working" message my goal is to instantly perceive exactly what the problem is and give a succinct, clear and correct answer. Now that is to some degree tongue in cheek but I hope you get the idea. One starts with the most obvious then goes on to the probably and finally the possible. I'm not going to hit it right first time every time, but as I say I'm learning.

So to answer the question .... if you can use Morph Manager to put the required morphs into a standard V3 then you are good to go. Convert to the V3 with those morphs, save the converted clothing and use that clothing with your custom V3.