I probably fall on the side of the fence to agree - if you blueprint a Remington factory action, you have neither a factory nor custom action. Sure, it has been customized, and it comes with some custom action COST, but it doesn’t carry any custom action value. I’ve payed a lot to blueprint a lot of actions over the years, added performance, but have never added a penny in value.
Doing a “custom paint job” on a Honda Civic is custom work, and the result is a custom car, but all of that money spent is sunk cost when it comes to resale value - sometimes even detracting from resale value. There were a number of years in the late ‘90s where you could buy a used gunsmith blueprinted Remington for less than a used factory state action - folks knew if you blueprinted it, you used it, and the fact you were selling meant it either didn’t perform to expectations, or you used the leather out of it...
I have 5 Ruger M77 MkII and Hawkeyes in my safe right now, blueprinted, custom barrels, custom stocks, aftermarket triggers... none are worth even a modest fraction of what I have spent on them.
So maybe a better way to say it is: “customizing a factory action is never an investment.”