shingles over touchdown?

Hi folks,
I’m working on shingling an overhang addition to a shed with an oddly pitched roof. I had a roofer come out and install a cricket in part of it, with torch down over. Now I have one overhang that is touchdown but am hoping to have it match the new one I will shingle. Is there any risk in shingling over the existing torch down? Anyone have any advice for this type of project?