Short answer is yes. Longer answer is I’ve got both WD40 and Plus Gas in the shed and I don’t think I’ve really noticed much difference in freeing ability between the two after many years of using both to free stuff off on old cars and bikes. That said, Plus Gas is noticeably lower viscosity and it’s specifically for freeing things off. I tend to default to it for old screw threads and I’d definitely choose it for alloy-on-alloy stuck seatposts. Best thing you can do is get some on there, put a bit more on from time to time and just leave it alone to do it’s job. Check it once a week.