Saving a pose with transformations checked will snap the figure back to the scene location it was in when the pose was saved.

Saving just the whole body scale alone won't work due to how Poser handles scaling.

You have to scale each individual body part in order for the scaling to be saved with the pose and not affect the location (transformation, which should actually be called translation).

You can save a scaled figure as a new copy of the figure's cr2 in the figure library. This will save whatever pose each body part was in at the time the figure was saved, including scaling. Name it something different so that you don't overwrite the original. I've customized several figures this way. There are a couple 3rd party utilities that will convert a cr2 to a pose file.

You can also export the figure in its scaled size and reimport it as a full body morph, tho that's not always recommended as it can screw things up regarding bits like eyes and teeth, it can be a quick and dirty way to begin an FBM shape. If you go that route then it's important that you not have the figure posed in any other way, only scale the parts you want to change sizes. It's also important that the figure is at its base resolution when you export it (if its a Poser unimesh figure like LF, LH, Pauline, etc). Then you would import it as a full body morph and use the match centers command in the parameter pallet so that Poser moves the joint centers to their correct locations.This can then be exported as an injection pose.