Very doubtful
"At any stakes higher than red chip with 200+ playing hrs/year, the time spent learning 100+ indices is trivial compared to the extra EV."
Now we know what's right for YOU! :-)
"I am not of exceptional intelligence or memory, but if I can learn ~90 indices in a few hours, it should take most of you less time than that."
That's plain silly.
"The index numbers are easy to remember for the most part because they follow a pattern, except for some of the soft doubles. I doubt that you will have to review index numbers on a frequent basis once you have them down."
Ten times sillier. You're deluding yourself. Learning them in visual patterns is great when you're RECITING them, and terrible for pulling the number up, instantly, when you're under pressure and trying to make a play. You don't have time for patterns then. You have to know the number COLD -- out of sequence, as if going through flash cards.
"At my betting level(green-black, not high stakes by any means) I estimate the EV from the additional index plays beyond Sweet 16/Fab 4 to be worth around a few thousand per year - a sound investment in my opinion."
Highly doubtful. Present your mathematical evidence.
Don