That's the beauty of the "no brainer" wonders, they save you more space
and more KP. Win win, no need to choose.
I mean if the "choice" is between upgrading 1 wonder 10 times to save 10 squares or upgrading 2 wonders 5 times to save 20 squares, its not really a choice
Upgrading 4 wonders to level 15 or 8 wonders to level 11 is about the same kp, and the 8 wonders will give you more seeds, more goods, more supplies, more pop, more everything while not costing you any more space, in fact if you pick some from the "no brainers" list then the 8 wonders will
save space compared to 4 wonders.
That doesn't even factor in if you add military wonders in the space you save and use that military to do more tournament for more kp compounding your gains.
Yet another point in favour of adding more wonders:
Nerfs.
Imagine you spend 1,000s of KP to upgrade the BTG or Enars(while neglecting others)only to have inno introduce the Trading Post that crushes the BTG, and mana buildings each event that make the enar's pathetic by comparison. Personally I'm super happy my BTG is only at level 6 so I won't be sad to sell it this chapter.