I haven't tested because I don't have those components. I'm planning to buy them. That's why I was asking.
If 1mm more is ok, what's the max extra height for the fan that I can use?
The clearance is exactly 37.6 mm, which is the tallest CPU cooler that can fit without interfering with the side panel. Any taller than that, and the side panel will need to be either left incompletely screwed into the frame to leave a gap or flex slightly. For 38 mm, this is not a problem because 0.4 mm will be unnoticeable. For every millimeter over 38, you would need to leave a gap equal to the difference and possibly get slightly longer replacement screws. The maximum extra height will depend on the gap distance between the frame and side panel that you can tolerate.
For the Velka 3, the top vents not being uniformly milled with circles and the bottom being 2 halfs screwed next to each other instead of a single unibody shell is bothering me a lot. Any chance those improvements can offered with slight price hikes?
Top vents: I would do this, but it would not make a substantial appearance upgrade without other refinements to complement it. Once the lineup of the current cases is complete with a focus on portability, variants focused on appearance with neat vents, perfect lines, concealed screws, etc. can be made.
Bottom being two halves screwed in next to each other: This feature has been changed. The top, front, and bottom are one piece and side panels are flat.