Not necessarily I believe, if you can limit yourself to instructing for the LAPL(A), rather than the PPL(A), then you won't need CPL TK anymore after 17th September.
From CAP804 Part J and presumably lifted straight out of EASA Part-FCL;
FCL.915.FI FI – Prerequisites
.....(b) additionally, for the FI(A):
(1) hold at least a CPL(A); or
(2) hold at least a PPL(A) and have:
(i) met the requirements for CPL theoretical knowledge, except for an
FI(A) providing training for the LAPL(A) only...
I know there are other requirements in there, but I've just quoted the relevant bits. (my bold/underline)