I see no problems here. Do remember that for Fxx values above 20 (hex) you are changing the Tempo and for any thing below that you are changing the Speed.

Yeah, this is a bit of the fine print about the F effect -- it can change two different settings depending on what the parameter value it. (The threshold used to be 0x10, and IMHO that is more intuitive, but whatever, no big deal.)

Frame 0C is your problem -- what tempo do you need it to be?

Also, protip: When you want to cut a measure short and proceed to the next frame, issue a D00 command (instead of a B command).

Thanks for the tip about the D command, seems less complicated.