@casper Hello Casper.... I don't know, but I do remember giving up (completely) on Jack for windows about 10-15 years ago. It just didn't work (back then).
If PD becomes very unresponsive then normally there is a mismatch in mediasettings between Pd and your soundcard, and as Jack is a virtual soundcard.....
What are your jack settings..... samplerate, buffer, bitrate etc. and can you match them in PD mediasettings? Have you tried ticking the "callback" box?
Otherwise you could try this.......http://vb-audio.pagesperso-orange.fr/Cable/index.htm
which gives you one 8-channel virtual connection for free. If it works for you then you can add more by making a donation to the author (of what you feel it is worth to you).
Thanks for making me research this.... I will try it myself, as it could be useful some day!