P0588R0 contains the rationale explaining why the rules for implicit capture were changed in order to capture some variables that are not going to be odr-used anyway.

However, it makes the rules too simplistic.

For non-generic lambda, the paper says "Note that we propose applying this treatment uniformly to both generic and non-generic lambdas (this is not essential to the proposal, but seems to give a more consistent language rule)." This consistency is useless. It does ease the workload for some language-lawyers, but the impact on the average developers is redundant captures.

For generic lambda, the rules can only apply to expressions in constexpr-if, and the condition of it depends on a generic lambda parameter.

This is enough to solve the problem to be solved in the paper.