So I am sure the Rams agree with you on that. Also him being 30 means he's still a good bet for a short contract of let's say 3 years, where they can expect to get his best for this remaining playoff window with Stafford. All told I agree he's the dude you lock up between the two guard spots.
Doing that by the way gives the Rams 2 OL being paid, those being Jackson and Dotson. I figure the Rams may be willing to go to 3 OL being paid, but I don't think that's a sure thing.
So looking at the remainder you have LG (Avila), C (Shelton), and RT (McClendon). I don't think it is wise to lock up Avila, as his play has been inconsistent so what's gonna happen when he gets the bag. I don't think it's wise to lock up Shelton, as he's a liability when defensive fronts isolate him. This leaves McClendon, who played well for us in a one season gig last year, but the Rams have been burned prior with Noteboob who showed well in limited action but couldn't handle the weight of defensive gameplanning as the dude.
Translation is I agree Dotson's the only OL who warrants an in-season extension, particularly if it's early in the season or even prior to it. If McClendon plays well throughout 2026 and stays healthy then sure, lock him up before the playoffs or whatever.
