On page 343 of the latest version of the TechManual (3rd edition, 2018) lists "N/A" for the ERLL under the Protomech entry.
However, older versions list it as taking up one slot.
Additionally, the Sprite 2 retains its ERLL despite getting a once-over in errata to removed the overweight Light TAG.
Nothing in the errata file for TM describes any change to weapons, save for what can be gleamed by the fact that several new weapons have ammo weights.
Was the final ruling from
here rescinded?