I think it's straightforward. If they're an investment, they're an investment -- your actions can depreciate them. If they're a tool, they're a tool, one that's either engineered and built to withstand real use, or not. Go one way, go the other, you'll be fine. I think trying to do both amounts to performing penance.
I don't think any one approach is superior, I think that like the knives we discuss, each approach is a tool to choose and use if it suits your needs.
Microtech make legendary blades and you, having attained the position of owning a bejesusload of them in a year's time, are in market intelligence terms, better positioned than most people to see what's best about them. You're also in a position to see early on what others might not see, as you indeed have -- which is that on the resale market you will really need to have left the knife in its box for it to attract top investment dollar, that the people who think 'eh a little light use won't be a big deal if I need to resell it' will be in for a shock. Either way there's a rub for you, because you like holding and using the knives you're buying, but you are seeing them as investments as well..
I think you need to choose whether you're the guy who has the complete Microtech collection or you're the guy who buys and uses the Microtechs that will not show light wear because they'll have better resale value. Not sure you've considered it but you could also be the guy who capitalizes on your market intelligence and buys several choice black Microtechs and leaves them in the boxes in storage, planning on cashing in on the fact that 'true black original clip' will probably be a selling feature in 2026.
I mean you don't really need to choose, but you'll be bothered by it until you do. Frankly this is all why I look for functional value more than resale value, I'm not a businessman, just a guy who thinks he who dies with the most worn out toys probably had the wildest ride. Lots of other ways to see it. :)