This design is correct? (6th order bandpass)

Hi. I have built a vented enclosure what performs good in real for this speaker below using SBL and stock parameters from the database - using the WEB designer. My project(s) is (are) shared too on the speaker's site (in database):

I want to design for it a 6th order bandpass the same way like the vented. This design below is my first ever properly designed 6th order bandpass enclosure what seems to be it is usable / buildable / compact, and performs a little bit better like my vented enclosure.

My requirements: at 30 Hz and higher frequencies using stock Pe (max power): to have ideal power handling (not overpass Xmax) + acceptable group delay (I will use it for music listening).

The only thing what I do not understand, this is plausible for this speaker if I use big ratio - 1:5, and the high-tuned chamber I tune super-high - this is just strange for me, especially the Fb. So if I design this with a bigger high-tuned chamber to reach a normal lets say 1:3 ratio, the power handling and group delay will be a little bit worse + if I use a normal frequency for it, lets say 60 / 80 Hz, the Cone displacement goes up so high that it runs out from the graph + power handling is total wrong.

This is the reason why I want to ask you that this 6th order enclosure is OK, or it is totally wrong?

Thanks for the answers.