Gave this a little go. The web version was giving me IO errors for any file I tried to load in. The desktop version worked a little better and could render some smaller files (~30mb geopackage, 300kb SHP.zip).

Trying to load some bigger files >1gb kind of just sat on 'Importing data...' for a while, then the screen went blank and I lost all my layers.

Got mixed results with a grab bag of other spatial files I had laying around. A lightweight alternative to QGIS would be good but it feels like this has a way to go.