You then need to be careful about the temp of the tool which if hot enough can melt plastic components or harm them. Keeping the heat source (heat gun) far enough away from the object that you’ll eventually melt the glue but would be much harder to melt components. I try to keep 4” or 5” gap between the source & object

You could try using an old screwdriver & carefully adding a dab of superglue to the screw to attach it to the screwdriver, Then the screw may come out, Superglue’s strength is holding 2 pieces together when the stress point is pulling the 2 pieces away from each other. Superglue becomes surprisingly easy to break when twisting the 2 pieces. So be careful since the rotation of the screw will put the stress point at the weakest of the glue’s strength.

The codes are not transferred. Certain components are have an ID number similar to a MAC address. The components have unique IDs & are registered with the hardware at time of manufacture, When replacing some components, like an LCD display, the unique ID components are transferred from the old part, the LCD display, to the new part, This maintains the functionality of those components, Replacement components need software only available to authorized Apple repair centers to add the new component IDs to the unit. In features like FaceID, this increases the security of iPhones by making it much more difficult to exchange components used by FaceID with components which have been hacked to make it easier to corrupt the iPhone security or for less reputable sources to sell cheaper fake components,

FaceID is diabled if the hardware detects a new FaceID module. Using the original parts avoids this issue so that the FaceID feature is’t disabled. This could prevent a FaceID module from being replaced with a doctored or unlicensed part which may fail to provide the same level of security than the Apple supplied part.

Apple’s point is that a device done well doesn’t need repairs. Until I dropped a large glass paperweight on my MBP-R 2012 display I had no need for upgrades or repairs. I have a maxed out version & still have plenty of room to expand I still recommend AppleCare.

If this is a rubber cement based glue, then would rubber solvent / thinner like N-Heptane help the removal process without damaging the black paint ?