Would more lifeboats really have helped?

If launching Titanic's existing boats took nearly all the sinking time, would carrying more boats actually have helped?

Yes. More boats in the water could have carried more evacuees and recovered more people quickly, even if not every boat was launched.

Additional boats would still have improved the outcome even if the crew could not launch every one before the ship sank. More craft already in the water would have created more places to pull survivors out during the brief period before cold incapacitation. Extra capacity would also have reduced the time spent deciding who should enter each boat before it was lowered. This does not mean that every life would certainly have been saved, only that the emergency would have been materially less deadly.