protobuf: features not available after loading/rendering

Hi,
in the geojson-vt variant I'm able to access tile features after the map is rendered, e.g. in a click event handler. I have a scenario where interacting with the map is important, clicking single polygons or selecting groups of polygons in a drawn rectangle or circle. To implement that I need to access the feature geometries and tags contained in the tile.
In the protobuf variant all feature info is thrown away after the tile is rendered and I'm not able to access the polygon geometry any more. Would it be possible to cache the features just as the slicer does? Memory constraints won't be any different than with the slicer, would they?
-Thomas

Start by tracing the protobuf variant's tile-rendering path and compare it with the geojson-vt behavior described in the issue. Done means polygon geometries and feature tags remain accessible after rendering, including for click handlers and selection interactions.