1) Mark the file with the read-only attribute, or use the /readonly command-line flag to open the file.
https://kinook.com/UltraRecall/Manua...linesyntax.htm
Also see
https://www.kinook.com/Forum/showthread.php?t=3728
for ways to minimize file changes when not read-only.
2) You need to use backup/sync software that supports block-level delta copy (of only the modified parts of a file).
https://www.google.com/search?&q=del...y+backup+cloud