Update after 2 days :
Temps are much lower. Nor the CPU or the 2080 ti will exceed 45C while playing Apex Legends at full specs 2K 144Hz for 2 hrs. Opened the case afterwards, feels way cooler inside than the previous case. Fittings temps are decent.
To sum up, the initial configuration had many flaws.
1- a lone 240mm rad for both a last gen i7 and an OC 2080 ti.
2- The rad was blowing hot air directly to the reservoir, crossing the case and was exhausted on top & read.
Now, the 3 right side fans are bringing fresh air which extracts part of the reservoir heat (there's heat sinks on its back) and most of the heat is extracted directly to the outside by the 280mm radiator. Only the 240mm rad will pull some heat inside the case but it will not stay here for long.
We will see how it goes in the next weeks and myplans for the future are adding a 360mm rad to the right side and eventually someday swapping the 240mm at the bottom with a 360mm for even less noise