Roy Smith wrote:

I don't see anything in there about 300 feet.

This is what the guidance to procedures specialists says:

j. The use of notes to prohibit a final approach from a holding pattern has been
DISCONTINUED. The following guidelines apply:
(1) Where a holding pattern is established at a final approach fix in lieu of a
conventional procedure turn, the minimum holding altitude must meet the altitude
limitation requirements of TERPS Volume 1, paragraph 234e(1).

NOTE:
Holding in-lieu-of PT at the FAF is not authorized for RNAV procedures.

(2) Where a holding pattern is established at an intermediate fix in lieu of a
conventional procedure turn, the rate of descent to the final approach fix must
meet the descent gradient requirements of TERPS Volume 1, paragraph 234e(2).

(3) Where a holding pattern is established for the missed approach at an
intermediate or final approach fix, and a holding pattern is used in lieu of a
procedure turn, the MHA for the missed approach must conform to the altitude or
descent gradient requirements of paragraph 855j(1) or (2) above. Missed approach
holding must not be established at the FAF for RNAV procedures.

(4) Where a holding pattern is established for the missed approach at an
intermediate or final approach fix, and a holding pattern is NOT used in lieu of a
procedure turn, establish a conventional procedure turn to permit pilot flexibility
in executing a course reversal and descent to final approach fix altitude. This
paragraph is not applicable to RNAV procedures.

Trying to get the AIM to conform with design intent is an unending game. Why don't
you contact AOPA and have them get the AIM corrected?