Directories with many files are hard to work with.

WinSCP seems to re-read directory contents about every 2 minutes. While WinSCP is retrieving the list, the UI is blocked and the program is unresponsive. When working in a directory with several thousand files, over a VPN, it can take almost a minute to get the list of files. That only leaves about a minute or so do to any work before the UI is blocked again. Sometimes actively working in WinSCP seems to delay the directory re-read, but still, every few minutes it becomes unresponsive as it reads the directory contents again. Is it possible to control the time between directory re-reads. It would be nice if the directory listing could be run in a background thread so that it does not block the UI.

P.S. I just noticed this in the log.
Could you use a different command to keep the session alive instead of a directory read? Maybe pwd?

I'll look into it.
Meanwhile, do you have to have the keepalives enabled at all? Cannot you just turn them off?
https://winscp.net/eng/docs/ui_login_connection

Thanks for the quick reply. Turning off keepalives did fix the issue, but then I get logged out after a few minutes of inactivity. Better yet, I changed the protocol from FTP to SCP (not sure why I ever set it to FTP) and used null packets for keepalive. Now I have the best of both worlds. Thanks for helping me sort out my confusion.

Good. I've improved this anyway:
Issue 2244 – Do not use directory listing to keep FTP session alive by default