I normally use simple sRGB working space in Octane as most of what I do ends up on web browsers. I generally write out tonemapped EXRs and comp in AE. This way my footage comes in already correct. Saves a step. However I noticed when using multi-layer EXRs, tone-mapping seems to clamp the data. Where as regular EXRs saved with tone-mapping don't.
Not a huge issue as I can simply save out un-tone-mapped files and apply sRGB in AE.
Just passing this along.