I don't have a lot of experience using my Pentax cameras with a gimbal, but we have Tilta GH-2 gimbals at work for use with our Lumix GH-5s cameras. The Tilta works well once you get it balanced out, but I found that having my camera in a cage seemed to screw up the weight distribution and made it hard to get it balanced right. We don't have a lot of time for our shoots so using the gimbal needs to be something I can do as easily as switching lenses. I found myself not using the gimbal because it just took too much time to set up. I tried using my Pentax K-01 instead so that I could pre-balance the gimbal, but since it doesn't autofocus when recording, I had to be very careful about my distance to my subject. I bought a Lumix GH-4 with the intention of dedicating it to the Tilta gimbal and leaving it on there all the time, but haven't yet done that because I keep using the GH-4 for other stuff. More recently, I bought a GoPro Karma gimbal to use with my GoPro Hero 5 Black and I really like that combination. It's so easy and handy to use that I've almost stopped trying to make my big gimbal more useable. In addition to tamer situations, I've used the Karma while speeding across a lake in a bass boat, as well as when I was on horseback on a trail ride, and it's given very steady footage. That said, it's only marginally better than the built-in stabilization in the GoPro Hero 7 that I have for work. The video quality of the Hero 7 is better, too, I think. Price-wise, it's probably a wash. I paid about $105 for my used Hero 5 on Ebay...and $100 for the Karma gimble, new. For around that same $200, you could probably find a Hero 7 now that the Hero 9 is out. Now you know pretty much all I know about gimbals.
How were you thinking of using your set-up?