The user interface that is currently available is kind of a preliminary UI because we needed some place to put it, but probably it won't stay this way. And hopefully you won't need the functionality to open/save a settings file that often.
Another comment regarding your picture: Once you understood how the load/save worked in the old UI you could operate it pretty quick. But we heard from many users that it's difficult to understand in the first place.
We work in different projects and therefore we save the settings to the project. So for us a simple setup like version 2.5 is much faster, easier.
I ask for help and not good advice that is not helpful.
Therefore, unfortunately we can not test version 2.6.
maybe someone can send me an email
and explain how he does it in version 2.6 (Sketchup pro 2019)
Thanks for your help