100%Items-Low%Map analysis (without OoB and without leaving corresponding map-squares, without activating Spazer+Plasma simultaneously, but distinguishing cases according to GT-Code): (unfinished)
Map of all necessary map-squares:
This section here is so far completely solved, except SuperJump applications, such as potentially beneath the Craterian SuperMissile, and beneath the Gauntlet Missiles, and (as stated in the section on the generally necessary squares) in the last Tourian escape room in Tourian, and in the room with the gates before Ice to skip the square in the room to the middle left of it (which actually seems likely to be possible), and in the room above Crocomire to get up in the short shaft to the right while skipping a square, and in pre-turtle room to skip squares on the way out (via SuperJump into solid blocks to start (inbounds) X-Ray-Climb there, and in Mainstreet room to get the SuperMissile via SuperJump instead (which seems likely to be possible aswell).
Independent of the used route, the blue squares will always have to be activated, the violet ones will have to be entered. For all grey squares there are methods to construct (TAS-)routes (for NTSC and PAL) that complete the game with 100% items without breaking any of the given rules.
Currently best approximation: