The new panels should be all you will need. This issue for Hot Spring has not been a spa frame issue, but rather, a panel issue.
Its not too likely many manufacturers would replace an entire spa for problems on the panel.
I was calling on a spa guy one time when a customer came in just as mad as could be. You see, his spa never worked correctly from day one and now he demanded new spa. He was quite adamant about it and very loud.
As the owner spoke with him, it turns out his stereo didn't work. I guess a screw was supposed to be removed before inserting a CD into the stereo. The installer forgot to do that. Then, the stereo "ate" a CD. So, he had issues from day one with his stereo. Yet, he demanded an entirely new spa because his didn't work. Now, the pumps, jets, heaters, water fall, etc all worked. He just had a defective stereo. No way he was going to get an entirely new spa for that.
Not that this is the same issue as yours, Asta, just thought I'd share a story.