The new translation attracted new users :) I'm relaying his feedback:

1. The add transfer window does not show remaining free space on disk
2. The add transfer window does not show the size/amount of currently selected files (indeed only transfer's total)

Further he complained that the window did not save previously selected folder location. I have 2 suggestions for this:
1. Always show "apply to all" checkbox, but grayed out to indicate that such option exists (questionable whether users will actually pick it up)
2. If no categories matched/applied: automatically choose the last selection.
I have not thought enough whether the last selection should automatically overwrite the global default setting (i.e. persist between restarts) or whether the Add Transfer should revert to global setting if it proceeds due to a timeout (as opposed to manual 'Start'). Should last selection be applied to all new transfers or only those added since last restart (e.g. old hanging magnet-links that come alive - should they select last selection or global default?)

I've told him about categories, but unfortunately they are not shown by default in Tixati - every other client (qBittorrent, uTorrent...) does show them by default and I argue this should be adopted too.
While at it, I do not see a reason why 'Bytes UL'/'Ratio' columns are hidden by default. There's enough space for them in the default ~1000 px window.

I think all of the above are valid UX proposals
Thanks dev