Yes, checking should take less than 1h, but adjusting them might take some time. Removing camshaft etc but 3 h should be more than enough.
Check them yourself and if its out of spec have the shims replaced.
I think the shims has 0.05mm between each size.
My biggest worry when i did it was keeping it clean, so i didnt get dirt inside.
I have a 09 Fe, but almost same stuff.