I recently retried with OH 2.5.x. Same issue. Then I tried reorganizing my Things file. Previously I created a Thing for each physical KNX device that I own (actors, pushbuttons, presence detectors etc). Now I have grouped all similar devices under 1 Thing so I have way less Things. So now I have a Thing for all my switch actors, one for all my dimming actors, one for all my PD’s and so on. Basically I went from ~50 Things to about 10.
Result: now it is very responsive.
