We put a level on it today and it is flat.
The bubble was right in the middle horizontally and half in half out of the bubble vertically using a 4 ft long board across it.
The patio is concrete and 30x12 with an overhead awning.
If measuring length wise your bubble was half in half out I don’t think that is so bad. That’s about were mine was.
Now that was over only four feet because you used a four foot level. If your tub is 7.5 or longer then using an eight foot level would give you a better idea.
The most important thing is to make sure is your filter is on the low side.
If you’re like me and need a level water line it sounds like you could shim it.
You need to check your owner’s manual/manufactures information on shimming your particular tub.
I bought a HS and the tub I bought could be shimmed and instructions were in the manual.
However, HS has two bigger tubs that they say should not be shimmed due to their weight.
For warranty purposes I would only go on whether the manufacture lists this information.