Carrier conversions and treaty replacement tonnage

Could treaty signatories replace capital ships after converting them to carriers?

Not under the treaty as written; making that possible would require substantial changes to its wording and tonnage rules.

The treaty allowed something close to the conversion idea, but not the proposed automatic replacement of capital-ship tonnage. The status of ships such as Courageous, Glorious, and Furious was already unusually complicated. Converting a slow battleship could also produce a slow carrier that hindered the battle line. Granting replacement tonnage as well as conversion rights would therefore require extensive rewriting and would still leave each navy with different design choices.