I agree about with the global HP/LP filter in concept, but (playing devil’s advocate here) that may get doubled up / be redundant / cause confusion with the filters already present in the individual algorithms. But a multimode filter – automatable parameters – variable steepness – resonance option … now we’re talking.
As for the Boss DD part (I only have a retired DD-20 here) … I might be misunderstanding here, but I consider the H90 delay algorithms without a filter to be more the exception than the rule. The newer algorithms with many more exposed parameters, yes. No filter options.
