Ok, couple of clarifications.
Outpost were never free. You had to pay for them by making pioneers, instead of making something else. I am not for free outposts, i am for decreased price.It is the same thing with other buildings, and troops etc. If they do not cost population it does not mean they are for free. Regarding conclave - if it does not cost population - in your words "It's a free lunch something that should never be in a strategy game because it's a no brainer". I understand that you also want to remove heroes improving growth and all the buildings that improve growth (unless they cost population). Following that we should not have building that provide guildar and yet does not cost any guildar, nor we should have buildings that provide mana and yet does not cost any mana and so on. This 'no brainer' idea of yours require profound reform of current game, we just have too much 'free lunch'.
I was not clear about 'stacking' outpost/conclave. If you have 6 conclaves, as you suggested, you have +6 to growth. I am not sure about it, but if it is a case, then i consider it a bug. Such strategy should not be valid, it is more the abuse of a system. When conclave do not 'stack' then you have just +1 growth, which cost you 30 turns to get back. In this case, whether you have outpost/conclave does not really matter much.
I understand also that you think leveling cities is unimportant. Well, we disagree here - and it is a problem with design. Leveling cities (all the more that we try to limit spam) should be fun, or just remove it.
I agree outposts are very, very important, hence should not be expensive. That was my point. Now you can afford outposts when: you have good number of cities established and leveled up to second level. Since pioneers are so expensive, they become rare, when they are rare, you are forced to build city rather than outpost. Strategically speaking, that's the way. There is just way more profit from the city than from the outpost. Once you have all cities you want to build then you think about outposts. I do not like it much.
I never used to spam 'pioneers' carelessly. Play insane and every decision matters.
And finally, here is the point where we truly disagree. I think the plan was to slow down city spam, not expansion. When i have now free shard 6 tiles from my city, i know i will get it in a middle game, even though it is so close to my city. Why? Because i am not going to waste pioneer till i have no other option. Hence i can have lots of cities span through continent and yet not have all this singular resources connected. Paradoxically, i am spamming cities now more than before 