Question about Canon Underwater housing WP-DC54 for G7X

Unfortunately, the answers are somewhat contradictory, so I'll bring the question up for discussion once again... I would like to replace my Powershot G7X with a new Powershot G7X Mark iii, but I would like to be able to continue using my old underwater housing WP-DC54. Of course I know that there is a new underwater housing WP-DC55 on the market (offered for the Mark ii). But this is not specifically designed for the Mark iii either. So I would like to ask again whether the old WP-DC54 housing works just as well for the Mark iii and whether all the levers/buttons for the corresponding operation on the camera then also fit. It would be nice if someone can really judge this from their own experience and has actually tried it out. A blanket statement that there is a new underwater housing from Mark ii onwards is not so helpful here.