The fact that anyone answered is strange to me. How can we give a GOOD answer if you don’t tell us your intentions? What kind of music do you make? What kind of bass sounds do you want? Do you want mainly sub bass or sub bass + mid bass? Do you want snappy/plucky envelopes? Knob per function? Live use, studio use, or both? What is your synthesis skill level? Do you care more about sound quality, workflow, ease of use, footprint?
Given the gear that you’ve already purchased, I get the feeling that you haven’t yet found “the sound” that you’re looking for. I feel like the missing piece in your current setup is something with more character. The three synths you have are all similar in that they are “safe” “all-around” synths. No disrespect intended, they are all great synths, but they are fairly straightforward choices in the current landscape. I’m all for getting some straightforward synths that have a lot of scope and range, but after that I think it’s good to get one or two strange synths with unique character that are hard to miss.
I think we could all list off bass synths for quite some time, but if you want us to list of the ones that will actually suit your needs, we have to be aware of your needs first.