In theory one should use values that are unlike to conflict.
20 and 24 are “too even” (not coprimes) for my tastes, after 12x20 minutes renewals, the timing could overlap with 10x24, and probably something bad could happen.
Personally I would use, since on the mac side it is fixed at 24, 19 or 23 on the Mikrotik, though in practice I don’t think it will be an issue, as there will probably be anyway some delay that will not make the two renewal times exactly the same.