PartSurfer "SPS-SENSOR BD" on 8/8 (not itemised in the MSG tables; Interactive Part Locator title "G-sensor Board" seen only as a search snippet, not opened). Sensor board = I/O Board (042 L90433-001 / 046 N01958-001 / 048 M47194-001 precedent). EMPR + vivacitytech name it. Listed for all 8 checked SKUs. OEM parts list only; not bench-tested.
Source notes
Saved HP PartSurfer product BOM(s) on box (partsurfer/cache_<SKU>.json, captured before this loop; no new HP fetch, HP OEM cool-down ON). Listed for 8 of 8 checked product numbers (1N5R1US, 1Y4D1US, 1W6P5US, 18X38US, 3D323UT, 1A769UT, 1D4H7UP, 9UU57AA; 7 of 7 North American US/UT/UP SKUs; product name "HP Chromebook x360 11 G3 EE (8MM99AV)"). HP description: "SPS-SENSOR BD". Keyword: Unknown Keyword. OrderFlag: 1. (via MM-LOOP-050).