rocks, locks, and invisible blocks
yeah I was thinking that may have a chance at working, it's possible with floaty to just kind of ram into the slope of the track and bounce up. Furnace seems pretty hopeless, it's kind of encased in two layers of collision and floating in the air so getting it during the wallcrawl is not happening. Underwater Frigate can be collected from out of bounds if you're in a position similar to the early PB but touching the item with your feet instead of the tip of samus' head (though it might load too fast to get in this position?). As long as that sounds it'd take, it could end up that wallcrawling Live Grove Tunnel is actually faster for all I know.