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.
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.
To make clear; to clarify; to shed light upon.
Consider the following:
The production manager promulgated on the new quality assurance regulations for nearly an hour.
- to make known by open declaration; publish; proclaim formally or put into operation (a law, decree of a court, etc.).
- to set forth or teach publicly (a creed, doctrine, etc.).
Example of the use of "promulgated on" from [Merriam-Webster]:2
Her ideas have been widely promulgated on the Internet.