From a procedure designer's viewpoint, a Pans Ops procedure provides massive holding pattern protection that is, in part, intended to allow for sector entries. Therefore, so long as you've passed the fix on which the pattern is predicated, you CAN commence descent to the lowest holding altitude, if you wish. You can therefore continue descent, as and if necessary, to reach lowest holding altitude DURING the sector entry.
I don't know what's actually being taught, but that's the REAL situation... from a Pans Ops procedure designer's perspective.