Apologies if this has been asked before but my search-foo isn’t turning up a decent result. HDR light textures such as those form Hyperfocal Design or wherever must be converted from sRGB to ACES correct?
Even if it is already float linear, if it doesn’t have ACEScg (AP1) primaries, then those need to be converted. The OP referred to the HDRI being in sRGB linear, so although it does not have the sRGB transfer function, it does have sRGB primaries, which need converting to AP1 using a 3x3 matrix, which OCIO can do.