We have a Kohler tub/shower alcove on our 2nd floor, and chose to put another Kohler "larger, deeper" tub in our master bath.

I was frustrated when it turned out that only the unit itself is larger! The interior tub dimensions are the same!

(It would have been nice if Kohler made a note of this in the description, as I now assume it's to accommodate replacement situations.)

The "larger" tub just has a taller, deeper front, and a large ledge all the way around the inside edge.)

It's the tub that would end in NO fun at all!

Look, there are a LOT of alcove soaking tubs far better than what you currently have.

Below, 70 gallon capacity!!

https://www.amazon.com/dp/B002QB7I88?tag=brg_ana_33-20&linkCode=osi&th=1&ascsubtag=094437049-2-1175940641.1711925509&SubscriptionId=AKIAJO7E5OLQ67NVPFZA

Also? Kohler Underscore, and worth a look? MTI whose specialty is tubs