Wouldn’t it be much easier if you just installed Steam for Linux and let Steam handle all the launcher and downloading stuff?
Just so there is no confusion, you do not have to have a Steam EVE account, just your regular EVE account.
You start Steam and install EVE Online. Steam comes with an inbuilt wine and Proton (for Vulcan™) and it adds an EVE Steam account like Steam:012345678 or similar to your regular EVE account.
When the launcher says its ready, start your client with your account and ignore the Steam account but under no circumstances delete that Steam EVE account.