Hi,
From my understanding, as the FI is endorsed with:
(b) Instruction towards class and type rating for single pilot, single engine aircraft....
Then a LAPL Only instructor is able to instruct for the initial issue, revalidation or renewal of an SEP(land) rating [assuming the instructor holds the rating them selves] if the student is a current holder of an EASA PPL, CPL, or ATPL? After all, point (b) has nothing to do with a '/For LAPL(A) only' since you can not attach a SEP rating to it....?