Hi,
concernning the entity "not-repairable" flag, it is written :
"Used to specify that the entity can not be 'healed' by repair-packs (or construction robots with repair packs) "
Infact such entities are not repaired by robots, but they can still be repaired by hand with repair-pack.
Example : add a "not-repairable" on any base entity (I tried on the radar), damage it, and you'll see that you can repair it (but not robots)
Not-reparaible still reparaible by hand...
Not-reparaible still reparaible by hand...
My mods on the Factorio Mod Portal 

Re: Not-reparaible still reparaible by hand...
Fixed for 0.13.7.
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