I far from winged it, I started diving with every intent of being a Tec diver. I took my open water, from there every dive had a purpose behind it to learn new skills. One of my dive partners are a former army combat diver, and one completed the Navy’s equivalent. They put me through the wringer. I dove regularly, at 25 dives I got my advanced cert, and by 35 I’d completed my deco procedures abs and cancer nitrox. “Intro to Tec” is not a prerequisite for deco pro or advanced nitrox, it’s merely a suggestion for anyone not familiar with doubles, or the gear.
At no point did I wing deco, or go into deco without planning it. A desire to stay down longer/ go deeper, necessitated deco training. And I should clarify, half of my dives number 25-50 required deco, so doubly a quarter at that point.
Did I have a questionable instructor? Absolutely not, I sought recamendation from local instructors in my area, on who to go to in Florida. The instructor I chose, teaches all open circuit Tec courses, to include full cave.