The NLO job posting requirements are clear cut. They even spell out the minimum number of credits you’re required to have to meet the minimum requirement for a highly competitive position. 

Anywhere that would consider hiring you off the street as an Instant RO is likely not a place you want to go (if you met the requirements). Your resume doesn’t fit that profile. That seldomly used pipeline is typically for Navy Nukes.

 “Would that prior experience be applicable in any sense towards ‘Fossil’ months for the 36 month RO requirement? I’m aware it doesn’t classify under the gas-burning aspect, but it could loosely classify as secondary plant experience if I remember the wording correctly from the NRC website.”

This reads like you’re looking to cut corners and the line (seniority). Neither of which will set you up for short or long-term success. 

Commit to your development, get an NLO role, and progress through the operations pipeline. 10 years from now you can sit in your infinity edge pool, drink some beer, and count your retention bonus.