This has actually been known for a while, it's just not particularly useful in the current speedrun routes.

Flamethrower is only gathered in 100% categories and getting it without the Red Coat wouldn't save time.

Address Bomb has been skipped for a long time in any%, and you don't even need Grapple to do it - you can damage boost-teleport right through the corruption blocking off the Drone Teleport area with just the Trenchcoat.