When I choose to display Large Thumbnail View in Swatches panel’s flyout menu, I expect Ai to respect my size choice and remember it, when I use the two buttons in the panel itself to switch List / Thumbnails modes.

Instead, Illustrator forces it to Small (which can be OK, since I never chose the List to be large) and does not even remember my previous choice when I switch back (which is totally not OK).

See the GIF, please.
Love and honor user data. This is what we use the app for — to create data. This includes not only the actual artwork, but presets and UI settings.