Comment by GMoromisato

V3 booster has a lot of changes, including a brand new downcomer, an integrated hot-staging ring, and 3 instead of 4 grid fins. Chances of a RUD are not 0.

If Flight 12 blows up in space, they've already got Flight 13 almost assembled. It might delay them a month, maybe. But if a returning booster destroys the launch pad, it would delay them much longer--maybe a year.

With those stakes, it makes sense to not try a booster catch until they're sure it's going to work.