You can configure WinSCP to use UTF8 by default:
https://winscp.net/eng/docs/ui_pref_editor_internal

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The next version of WinSCP will default to UTF8:
Issue 2397 – Default to UTF-8 encoding in internal editor

I'm working from Win, with you excellent software on a Linux remote VPS, every time a file is opened, it starts with the 1252 ANSI Latin Encoding, even a file was previously saved as UTF8, so forgetting to change the encoding everytime a file is edited, it will be saved with different encoding from the original. Also sometimes it gives error while saving a 1252 Ansi when is changed to UFT8. I work with UTF8 files only, it happens that opening them in 1252 I lose the ascii formatting and Unicode characters. It would be great to detect the file type on opening and setting the appropriate encoding or remember the saved setting and reopen the file with the correct type. Thank you for your amazing software!!!