Thanks for the replies. I noted a while back that the trailer’s regulator is rated at 11wc and the griddle’s regulator is rated at 13wc, so I assumed the regulator on the griddle wasn’t really doing anything in this situation: JB’s and jimmarako’s replies seem to support this.
I’m not much of a griddle user, so I don’t think I’ll mess around with removing the regulator or replacing with a Blackstone at this time. Perhaps running it off an un-regulated 20lb bottle could improve the performance a little.
I appreciate the replies, thank you. This site has been a wealth of information for us.