you have correctly identified the built-in speed control as part of the solution. that's one of the reasons the machine has that feature. a speed control isn't quite as fancy-shmancy as a stitch regulator, but it is quite helpful.
if you have remembered to lower your feed dogs and your sandwich is still "catching" on something then keep watching this topic. i am definitely not qualified to provide advice on this one. my own FMQ skills are ... shall we say ... stinko. :lol: