Only the MX-3000 software can adjust the repeat output for learned commands. The MX-950 software can only do this for database commands and the 700-800-850 software does not have this option at all that I know of. Yes I actually had to change the frequency to get the buttons to work 100%. You might want to try this for your shutters. It works much better than raising the repeat. I actually had to turn down the repeat to 1 on most buttons.
I have some shutters also that I would like to change to remote. Can you tell me about your setup?