Why are you building wealth worlds at all? Did you try without them entirely?
I'm curious, because I don't build wealth worlds at all. I generate some income simply by upgrades to econ starbases and some by trade (maybe 2-3 trade buildings on that one planet... typicly my homeworld) and eventually tourism. And I pick Handy +2 as a racial trade. Very useful that one.
Maybe it is because of difference in map size... is it more useful, because it allows you to kickstart fresh colonies? I usually play on Medium to Huge... 4-10 planets to colonize early on.
I play on Immense or Insane. It really isn't about fresh colonization. I have sparse factions spread across the galaxy. Empires are easily 30-50 planets each.
I have been persuaded to try smaller maps with more factions and much tighter spacing. I would estimate starting empires as 8 to 12. The same principles are applied to my economy as in larger empires. They just don't achieve the same levels of positive feedback loop acceleration as quickly. However. if I start conquering, the feedback loop will start kicking in pretty quickly. Then I am back to swimming in Wealth, Research, and everything else. Please note that this is not a complaint.
In my late colonization phase, I have usually built a lot of improvements on my starting planets, improvements that start building up maintenance costs. Even if the planet is overall profitable, it will be by just a credit or two. If I don't start working up Wealth planets, that will start to mount up and the overall economy will bog down. So the Markets start kicking in and I start making appreciable money. This gets me investment in Asteroid Mines and cash for Diplomacy trades. Also, I like rushing certain key buildings. This all very good and keeps things accelerating throughout the game until late stage. Somewhere in there, the Wealth production balloons to larger numbers.
I could theoretically convert the Wealth planets to some other function, but, actually, I have the same issues with Research and Manufacturing. All my problems in life should involve too much success.
Presently, I am trying a different custom faction that doesn't fit my play style so well. At the same time, I am moving down from Incredible and Godlike. I have different abilities, traits, and tech tree. If sheer culture shock is a mark of successful variation, I am on the right track. We will see how it works out.