I have a question about doing all the Scouts at once at the end of the season for shitload of Season Pass XP because of Stretch goals?

Can I do like 2 steps out of 3 and activate another scout and do 2 steps out of 3 again or will my entire progress on the scout be erased?

Ever since Battlefield 6 release and beginning of last season The Pact released I have kinda fallen off the game after playing for little over a year and from SHD 20 to 3650 today. I have almost everything including max expertise and entire library but except Raid exotics because I play solo 99% of time. Lately I've been playing just for completing the Ubisoft Connect challenges which give you points for goodies across all their games.