Oh boy have I done a ton of steering stuff on the e53 lately. Dissected every piece of it.
Always start with cleaning the universal joint with a ton of brake clean. You will not believe how much crap gets stuck in there.
Don’t forget to lube it up again and maintain it as well. (Or buy a new one but€€€€).

Second I’d replace the rubber disc on the steering wheel side. Either for a new rubber or a poly/alu part. It’s crazy how much better the power steering pics up when there is no compression before the input shaft of the rack. (You’ll have to drill out those rivets so take some time for this)
Yes it might let you recognize a wobbly wheel sooner but isn’t that something you’d also want?
In short great steering setup but needs tlc due to age.

Hope it helps.