Hey Chris
While not particularly intuitive, there is a simple way to use your up/down keys to move through the Perform mode content while you are looping a chord or progression. Certainly not a midi-browser, but it might help while we wait. 
Simple Version; The key is to keep that list UI widget in focus after you’ve made a specific pattern selection.
With Perform activated and the loop playing [very important], select the pattern group (my term not Scaler’s) w/in Expression or Articulation (Performance, Bass, etc) you want and then click on the highest level menu/list “Pattern family” (the one that shows up on your toolbar) twice…once to open the menu and then the second click keeps the focus on that list but lets your keyboard advance up and down with out hitting enter. You can also just select a specific pattern but do not click anywhere else. The key is to keep that list UI widget in focus so have your chord pattern looping before you select your Perform pattern family. I’ve played every pattern in Scaler w/in just a few minutes
Here I’d just click on Accento (twice) and now I can move through all the patterns (under Accento) with my up/down buttons. To move to the next pattern group, you’d need to select a different top level pattern group.
A little more detailed description is here: Performance examples and favorites? - #4 by 1stInversion