Take their guides with a bit of a grain of salt. Having gone through Apple ACMT training back in 2015, many of the iFixit guides have recommendations or procedures that do not follow official Apple guidelines. In most cases it doesn't matter, but it can come back to bite.
For example there are torque specifications for some of the screws in the trashcan Mac Pro. I doubt getting the torque wrong would cause any issue, and Apple is probably being a bit pedantic. However, iFixit's thermal paste application article specifically recommends spreading thermal paste with your finger[1], which is a TERRIBLE idea and goes directly against Apple repair procedures.
So use common sense when working with iFixit guides, they should not be considered replacements for official Apple repair guides, though they are far better than nothing, which is what Apple provides to the general public :).
I don't give a shit what Apple thinks, and wouldn't bother seeking their opinion. I've replaced probably every part in an old MacBook Air I have and the non-Apple online documentation has been really good.
All that being said, thermal paste is pretty poisonous, I'd never even considered someone would just splodge it on with their finger.
For example there are torque specifications for some of the screws in the trashcan Mac Pro. I doubt getting the torque wrong would cause any issue, and Apple is probably being a bit pedantic. However, iFixit's thermal paste application article specifically recommends spreading thermal paste with your finger[1], which is a TERRIBLE idea and goes directly against Apple repair procedures.
So use common sense when working with iFixit guides, they should not be considered replacements for official Apple repair guides, though they are far better than nothing, which is what Apple provides to the general public :).
[1] https://www.ifixit.com/Guide/How+to+Apply+Thermal+Paste/744#...