That tool is a piece of junk. Don't waste time.
There speaks someone who has tried it, I don't know, never used it.
But let's face it, if you have to make modifications that will require a download, just "Go Online", "Save" (You will get a prompt that tag values may have changed... say yes to upload and save them), "Go Offline" , do your mods as quickly as possible, then "Go Online" and "Download".
If nothing was running while you did your mods, your "Run-Hours", however you have derived them, will be correct. and if some background process was running motors/fans etc., a few minutes isn't gonna be a deal-breaker in terms of hours run.