Positive euphemism for "harped on"

How can I replace harped on with a more positive expression?

The production manager harped on the new quality assurance regulations for nearly an hour.

dwell (on):

to linger over, emphasize, or ponder in thought, speech, or writing (often followed by on or upon ): to dwell on a particular point in an argument.

Though, it is usually used for negative things but not necessarily. It is a more positive expression than harp on. Using the preposition upon is more formal and less common.

expound: "to explain by setting forth in careful and often elaborate detail <expound a law>"

In this case, you'd probably want to use it with the word on:

The production manager expounded on the new quality assurance regulations for nearly an hour.

To wax lyrical:

The production manager waxed lyrical about the new quality assurance regulations.

A neutral version could simply be:

The production manager spoke about the new quality assurance regulations for nearly an hour.

Putting a positive spin on it:

The production manager spent nearly an hour elucidating the new quality assurance regulations.

https://en.wiktionary.org/wiki/elucidate

To make clear; to clarify; to shed light upon.