It's just slightly more resources in Antiquity, and clearly more in Exploration and Modern. I would argue that since 1.3.0, Exploration and Modern have less resources than before, so I'm not sure how it compares to resource generation in 1.2.6.
I will maybe reduce the number of resources spawning with this mod in the future, depending on how Firaxis adress the issue in future patches.

Will this mod increase the total amount of resources on the map? I do agree with the vision but I don't want to play with too many resources (less space for districts/wonders and more science/prod adjacencies).

You need to start a new game with the mod on.

Will this mod work in the middle of a save or do i need to start a new game for it to work?

Thank you so much for this mod! I really love acquiring resources in this game and I can finally have a peace of mind knowing my precious Rice resource will stay. Again, thank you!!!

This mod incompatible with JNR's Extended Resources
https://forums.civfanatics.com/resources/extended-exploration-resources.32296/

Nevermind I got it wrong it. It's actually JNR's mod making wool available in Exploration age and your mod made it guaranteed to happen.

Yes I have them spawning in the game or I else I wouldn't have brought it up

@kenichi03 It's already the case. No resource would stay if it is not supposed to appear in the next age.

@infinitesworld, have you checked before saying so ? Because Woold and Hides absolutely don't spawn outside of Antiquity. The reason why they were made staple is to guarantee their spawn. Otherwise, they would be too often left aside in favor of the resources that would persist.

Can you make it that only the resources that can appear on an age stays? To fix the problem with the first comment.

You have both Wool and Hides as staples in your mod, which makes them generate on the map outside of the antiquity age, taking up map space and offering no benefits other than resource adjacency.