I was in music theory class in HS when I started playing guitar.
Thus I learned scales on piano keyboard first because learning all scales maj/min-harm-mel over two octaves with both right and left hands was a requirement to perform. Sight reading to tempo was not a requirement. We spent plenty of time writing notation, mainly with a harmony focus.
Let me also add, I went to Plano Senior High School (west) which had a graduating class of 5000 students. This school is 2 years; Junior and Senior years. That means 10K students. After those that dropped out of the initial 20 students in my class, there were 16 students in my class. I don't mean to brag here, just to say that for those that chose to learn music theory we were a huge minority. And I have seen that similar minority in general population over the past 40 years.
Initially I had the typical Mary Had A Little Lamb intro to guitar. Then a friend showed me the intro to Bastille Day by Rush and I was hooked. A short time later, I started by learning songs from records on guitar by ear. I always felt more comfortable playing guitar, but visualizing music on the piano keyboard as I still do now today.
That said, for my viewpoint I have never been and never intend to be a covers player; original songs and improv has been my wheelhouse. I find live improv my preferred form of music. I do not consider improvising over known pop/ standard songs or progressions as improv, per se; for me improv is on-the-spot composition. All that said, I quit playing live many years ago
As far as 3NPS, I have no idea what that is...I go look it up.