I did not buy the tub yet. I saw it, looks okay.Steel with porcelain finish. But I see complaints about the stytofoam Pads that it sit on 5" off the subfloor. It states Has "Pads No Mortar Required" but they say" It is creaky as the connection between the tub and the styrofoam rub together. The old tub is in this 1952 house has never been replaced. So I do not know what is underneath. Or how the subfloor looks.
Your thoughts will be appreciated

The name " foam" in styrofoam says it all. Foam consists of air bubbles and they compress with age and use leaving space that can make noise when you put weight on it.
You should have a tub access m panel in the wall fronting the tub,
Anything you can shore the base of the tub would help. Boards, mortar or cement comes to mind. This is called "bedding" the tub. If the "creaking" disturbs you bedding the tub is your solution. Good luck, Tom

Very good