Not all cell tower searches are created equal.  A lot will depend on the client and on the state you're in.  The problem we run into here in Michigan is that if Cell company A sells to Cell company B, they don't always record anything that actually TELLS you that, and since we are a grantee/grantor state (no tract index in most counties), there's no way for us to following the chain.

 Most cell towers here are fairly recent -- within the last 20 years.  Probably the case that the vast majority are 20 to 30 years old.  (Who had a cell phone in the 90's?  Not me!)

Again, here in Michigan, we have to provide the vesting deed to the actual surface owner.  The cell site will be much smaller and on a lease.  Easements have never been an issue since all of my forms say "Information within the timeframe of the search ONLY."  There is no tract.  If they want a 20 year search, they get a 20 year search or there's an upcharge.  Usually we'll provide the true surface vesting deed even if prior to 20 years, but only if it's reasonable.

We charge MORE than a typical 20 year commercial because so many of these properties are just a mess.  I think the cell companies look for the most complicated piece of land they can find and then decide to bill there!  A lot of my abstractors refuse to run cell towers, and I refuse them if it's a tower in downtown Detroit (for example) because that means the tower's on an office building -- and who the heck wants to try to tackle THAT and assume that liability?  Since my insurance goes up to $1 million, I sort of put my foot down at that point.

Do lots of disclaimers.  Try to get them to accept "report limited to the cost of the search only."