TBH, I feel like all keyboard expression pedals pale in comparison to the Mission Engineering line of expression pedals. For whatever reason, keyboard expression pedals are almost all built like cheap plastic tin cans with no run, while guitarists get heavy-duty precision pieces of gear. Thankfully, ME has brought it's line of top-quality guitar-oriented pedals to keyboardists, and they're a huge step up from everything else I've tried (Fatar, Kurzweil, Roland, etc). I own an ME EP-1, It's very similar to a Dunlop Crybaby, which I've always loved the feel of.
https://missionengineering.com/product-category/products/expression/keyboard/?v=7516fd43adaa
The one thing I would look at is that Yamaha keyboards use a reversed polarity from everyone else, so if you're playing a Yamaha, you'll want to find a pedal that is compatible or has a polarity switch. I believe ME makes one, but you'll want to email them, they're very responsive.
A bit of information: All expression controllers are "dumb", being that they simply attenuate a voltage that the keyboard reads (between 0 and 127). The pedal itself doesn't create any effects, all of that is done in the keyboard, and the pedal input is simply assigned to control a particular parameter. I typically use mine for "wah wah" effects, since I do a lot of rock leads, but it can be used for other things like filter sweeps, volume, pitch... you name it. If you can program and assign it, an expression pedal is no different from a mod wheel or any other CC.