Definitely don't just switch over an aid programmed for domes to moulds yourself, it needs to be reprogrammed for moulds. If you are planning to get moulds, get them first then get programmed right, unless your coverage lets you go back easily and get the programming changed.
Domes can be OK, though, I have "powerdomes" which is a double full dome, works better for me than any traditional moulds ever did, they either came out all the time or hurt as I have a hypermobile jaw. I still have to shove them back in every time I eat or yawn and several times a day for no apparent reason, but they don't make my ears bleed that often! My favourite was custom tips, it's like a dome in size but custom made to impressions. Stopped buying them when they stopped giving a 1 year warranty as they fell apart sooner, but hope to go back to them if I can find a better warranty.