Any way to adjust infill within octoprint?

Not much else to say. I'm using the cura engine plugin (I believe it came by default) on the latest octoprint. Pi 3 B.

Install the Full Featured Slicer plug-in. It gives you access to adjust a number of variables in Cura, so you don't have to import a new profile for every minor change.

I assume you are aware that you can also run the current version of Cura on your desktop/laptop computer adjust any of the numerous settings there and send that gcode directly to Octoprint, bypassing the older version of the Cura slicer that is bundled with OctoPrint?