If they’re just created as ways or marked “highway”:“road” or something, and especially if they have been like that a while (a few days, a week or two, depends how active the area is - I usually go by what appears on the slippy map / mapnik layer rendering), then its probably ok to assume they’re not about to be updated. You can’t guarantee anything, but you can put details in your profile/wiki user page to show what areas you’re doing if you like and people hunting for other users and interested in coordinating will find it.

If you’re making data better, more specific, adding tags, then also I wouldnt expect to change them back to something worse, so you’re probably ok anyway. I dont know how well update merges happen on the server but they must have a mechanism in place and if a re-download of it fails for the next editing session you do, then obviously something’s happened or someone has manually reverted it for a reason. Just don’t leave it too long between fetching updates and I reckon you’ll be ok.

Note: disclaimer: all just ‘reckoned’ opinions from my own editing sessions, no actual knowledge of how things are handled/ how busy coventry is/ anything else appropriate…