Yep. Either you live with the constraints of one big page, or try to manage everything yourself.
Or, just don't worry about it. Many of my layouts have some pages that need both sides, while most don't. The index page has separate links to both 1/2s. The user can bring the right half up on the left side, etc. I add a visual cue that the pages are loaded correctly - a unique color line that meets only in the middle when correct. If you have the left 1/2 of the Jup 8 and right 1/2 of Juno 106, the colors will not match. If the sides are reversed, the lines don't meet.
And for a good laugh, look at the upcoming video on the new features in 2.5. I mean to bring up two 1/2s of the old version, then compare to the new. I bring up 1/2 old, 1/2 new, and don't realize until I try to go to the new. (Having an old version and new version in the same layout is a unique situation.)
Sometimes you cannot fix everything in code.