The Rams didn't have the same amount of OL depth in August of 2018 when they extended Havenstein as they have today either. It wasn't until 2019 before Evans & Edwards were drafted. Blythe also replaced Jamon Brown at RG mid-season 2018. And this doesn't reflect on any potential OT's that may still be drafted in 2021, so as yet, i'm not seeing RT depth as a problem if Havenstein is moved as a CAP casualty. Saffold's loss following the 2018 season, followed by Havenstein's injury in 2019, gave us Noteboom at LG and Evans at RT temporarily. Had Saffold remained, I would think that Noteboom would have been Havenstein's RT replacement rather than Evans. Fortunately, for 4 or 5 of those first games Evans played were rather exceptional and had the entire fanbase believing we'd found our RT of the future. Unfortunately, Evans tapered off those last couple games, fans came back down to earth and Havenstein was pardoned.
Unless we are talking about a Center, I see no current need for another free agent offensive lineman, the draft should be enough to serve our purposes imo.