In that case, replace "ignore" with "convince".
The "Open File" dialog of every OS has a shortcut on the left side to quickly get to the user's home folder, so whenever "last used folder" might be the wrong behavior, it is trivial for the user to get to his home directory. The opposite is not true.
On the Mac, the problem is even worse. If you search for the file you want to open and select it from the search results, there is some bug that causes Cura to do nothing (rather than open the file selected). Searching for a folder isn't even supported on the Mac. So you have to search for the file, select the item in the search results (But don't click open), then double-click on the containing folder in the breadcrumbs in the bottom of the view. Now that you are viewing the folder containing the file you want to open, you have to select it again and open it. Fun.