Do you know what is actually involved?
From what I can see (in simplified form), you pull the cam cover off and in sequence for each cylinder you turn the crank to have the cam lobe pointing upwards, you then check the clearance between cam and shim is in spec with a feeler gauge, if it isn't you remove the shim, measure it and then work out what size shim you need to replace it with to bring it up to spec.
Time consuming? Yes (if you need to make adjustments). Difficult? No.
There is no need for bodging. (But like I've said a million times, I probably won't buy one).
From what I can see (in simplified form), you pull the cam cover off and in sequence for each cylinder you turn the crank to have the cam lobe pointing upwards, you then check the clearance between cam and shim is in spec with a feeler gauge, if it isn't you remove the shim, measure it and then work out what size shim you need to replace it with to bring it up to spec.
Time consuming? Yes (if you need to make adjustments). Difficult? No.
There is no need for bodging. (But like I've said a million times, I probably won't buy one).