"What problems might I look forward to setting up the carbs this way"

one carb working (center)
two carbs blocked off (sides)

Of course, you are correct, Jon.

However, would the single "working" carb, as described, on a 3-carb manifold (as described) cause any problems?

Apparently, the issue is not performance.

The question seems to: will there be any negatives in performance, compared to a single carb manifold?