Well, I'd say "do it on your own risk". I'm not sure if I understand your point about "replacing doomsday patch" with another patch...
Tell you what, I always use Social Club and Launcher to update my game because I consider it safest. This way, effectively, you no longer have to worry where from to actually get the update from. TBH I find it rather unorthodox to look for it anyplace other than Social Club!
My call, would be to let the updater run online this time and just do it's job. Just delete what you don't need after it's done. If, like you admit, you are able to play the game offline, then I think you're good to go.