What things are you testing? If it’s really nothing to do with the way it looks cosmetically, then you will be fine with FDM. But for mockups for reviewers, you may want to just order them SLA’d from JLCPCB. I got a part made by them and the quality was phenomenal and it was super cheap and fast. It’s slower than printing it yourself, but the quality is worlds better and you would have to order hundreds and hundreds before it costs more than buying a printer.