With Rebuild being so awfully strong, I've been interested to see whether removing the "+1 Action" would balance it. I expected it to remain strong, while Donald X. said that this version "couldn't compete". Since I didn't know how to add new cards to the simulator, I just "simulated" this with the existent Rebuild strategy (by ragingduckd and SheCantSayNo) by setting "WantsToRebuild" to zero when there's already a Rebuild in play, which seems to work as intended. The buying strategy is still close to optimal. This "TerminalRebuild" turns out to be significantly weaker than the original card:

TerminalRebuild loses to the strongest BM cards: Wharf, Goons, GhostShip, DoubleJack, all Cursers.

It essentially ties with Monument (51:49), Envoy (48.5:51.5), Smithy (52:48) and Courtyard (50:50), and wins against all other implemented one-card strategies (Militia, Masq., HP, Amb., Library, ...).

So BM-TerminalRebuild is about as strong as standard Smithy-BM, i.e. far from overpowered, but occasionally useful on BM boards. This seems to me to be an interesting "mediocre" card: It'd be worse in an engine, but great for slogs, or when combined with Walled Village (making it non-terminal again) or Tournament.