Follow up in case this is useful to anyone else out there.
After my last post excitedly showing off my cube, I tried again to print my project files and they were horrible. The top half was smooth, the bottom half looked like the gnawed hull of the black Benchy that I shared in an earlier post…but much worse. This is unacceptable for my purposes even if I were to sand it. Again, I’m not looking for perfection as much as I am consistency across the entire print. This all led me to do a complete tear down of our A350 where I made sure to tighten and clean everything, switched out the nozzle kit for a new one and switch out the bed pad with a new one. (Before all this, I also printed the parts I had mentioned for the filament guide and heat bed cable protector. :D) The idea was for me to learn more about the machine and to create a better baseline for calibrations.
In addition to above, I also switched to using Cura by importing Snapmaker A350 print profiles (mentioned here) and plugins for both sending prints directly to the A350 (found here) and for calibration shapes (here).
After all that, I started working my way through the Teaching Tech Calibration steps (the ones that were mentioned as the most important) using all of the above changes and the test results so far have been very encouraging. Even the melty/gappy thing I was experiencing seems to have disappeared. I’ve learned a great deal in the last few days that has given me confidence in printing and in our Snapmaker.