they were deleted in new version of techreborn. reason: they not work. really? let's see.
this is the techreborn version 1.11.2 - 2.0.9.25

they work. at least they were. please add that slots again...
now you believe me @modmuss50 ?

I wasnt aware that they worked, I said I didnt think they worked.

And I wasnt the one that removed them, also please stop with the augmentative tone. They will be added back at some point.