Slight thread drift from retracting flap on touchdown but, I remember many years ago doing an FI revalidation with a very experienced examiner, the sort of guy who has forgotten more than I will ever know.
As I briefed the PFL exercise I made the statement once flap was selected, not to raise it again. This invoked the slightly raised eyebrows and the comment,''oh, why?'' and I realised I had dug a hole that I was not going to get out of.
We then had a lengthy discussion about the pros and cons of raising flap and rate of descent etc. The bottom line was, never say never, and the BA 777 at Heathrow proved his point many years later.
Flap is just one flight control to be used as and when appropriate.