i would say VXAO is the way i would go. unless you just render out the AO map and overlay it on top of a 50% grey texture then just import it
just a quick render of a mech, SSAO(default ue4 AO) vs VXAO
these are purely just the AO buffer visualizers, i’ve been really impressed by VXAO’s cleanness for real time AO
last 2 shots are just VXAO one directional light with shadows off and an 18% grey material with roughness at 1
you could also get the same or better results using lightmass, i just have no idea how