Does anyone have a instance of FCM 9.1 running on Tools 8.56

We are not ready to move to 9.2 FCM due to some business partner resource constrains We are currently running FS 9.1 on tools 8.53. We are trying to determine what level of tools we can migrate to. I have been getting conflicting information from a number of sources stating that you can't run 9.1 on 8.56 because it requires fluid, and the fluid navigation does not work with Classic pages. The thing is we are not wanting to use any fluid components so from what I see there shouldn't be any problem.

What I am trying to do is get it so we do the tools upgrade now and then when we do the 9.2 upgrade we will be able to just do a minor tools patch instead of doing an upgrade on tools as well.