Can I install both a Brix and Elements on one OPS?

This is physically possible, but it will not work very well as the Brix will open up in fullscreen and there is no good way to switch between the Brix application and the Elements software. In case you really want to use both, use the Brix on the OPS as usual and add a NUC or PC to the Canvas screen (with HDMI/DP + USB + network or USB-C) where you install Elements software. (Canvas has a cut-out in the back specifically designed to place a small PC or NUC if you want to)