Out of Central Casting

Too clever for me! I was looking in the centres of the themers, rather than the central columns of the grid.

The meta answer is FLY FISHING. The puzzle's title, "Out of Central Casting," is a phrase derived from old Hollywood days; currently, it's an idiom meaning having a nature or appearance typical of one's role or position. Here, of course, it has multiple other meanings.

It also hinted at the meta answer coming from the puzzle's center in some way. Conspicuously, 5 symmetrically placed Across answers were the surnames of notable actors. And these 5 surnames also intersected the puzzle's center. (Because this grid is 14 squares wide, that means its center has 2 columns instead of one.) From top to bottom and left to right, the 2 letters apiece in those 5 actors names that also intersect the grid's 2 central columns spell FLY FISHING, a 2-word activity (that's related to a non-acting kind of casting!) that satisfies the puzzle's hint.

Also loved many of the clues — 62A was my favorite.

Very elegant mechanism — too elegant for me! Thank you for the puzzle and the clear explanation.

One small nit: In 50A MLII is 1052 (while MDII would be 1502), so the clue is not quite right.

Got it! Not sure how I saw that, lol. Nice one!

Don’t think I ever would have seen that. My head was stuck in the IMDB. Thanks for the helpful explanation.

Yep, was too cerebral for me. I had the two central letters which ended up spelling FRESH NINTH. Initially I got FIRST and hoped I'd get NIGHT for FIRST NIGHT which is an activity of course and would have temporally appropriate (I mean this was published early January), but no such luck. You certainly do pick novel mechanisms Cory!

Very enjoyable! Didn’t have to do any googling, and found the meta by thinking about needing an ING at the end (since it’s an activity) and Channing had that at the end. So I thought just take the first two of the first, the next two of the next, etc. That obviously was never going to work, but it got me enough started on FLYF….NG that I figured it out after a bit. Thanks for the fun!