I think the most probable reason active sense is being ignored in the latest version of PD is because I reported this bug (and other midi issues) after fielding and confirming multiple problem reports on the PD web forum:
https://lists.puredata.info/pipermail/pd-dev/2017-01/020888.html
I agree that this problem (most likely) has nothing to do with the volume of messages; PD internal message bus probably has to handle tons more message volume than anything external MIDI could produce.
My main use (insofar as my own patch programming) for PD is modular MIDI control on systems running 16+ ports at a time. I've been working on it for years and believe me, there are numerous problems with the MIDI implementation in PD and I have quite a lot to say about this subject in general. I've been preparing a full list of issues to post here but I want to re-test with the latest version to see where things currently stand. It's really needed, there is a lot of confusion, missinfo and missinformation on this list concerning midi and the state of it's implementation in PD.