When we talk about energy scales, we often hear that we need new theories of gravity and particle physics when we hit the barrier that is the Planck scale. In particle physics we've only probed up to about 13TeV, which is way WAY below that level. It's easy for us to designate the energy to which we've probed, since we built the LHC and we know what energy it is operating at. My question is, what sort of energy level have we tested GR to? I'm guessing that the highest energy scales belong to the binary BH mergers detected by LIGO, seeing as the energy emitted from those mergers was colossal, but how do we pin down an energy scale in the same way as with particle physics? Where can we say with confidence that "GR is definitely valid up until xyz energy."?