"on the fly" slap-comp via command-line

I'm trying to create a "on the fly" slap-comp for Lighters but I'm running into a few road blocks as far as applying individual LUT's to the A/B. 

Need help in how to get this to work or come up with a better way.  Below is my command-line and the EXR looks like it's coming in un-premulted as well. The EXR does have Alpha.  Not sure how to get around this.

%PXM_APP_CONFIG%\rv\rv-win64-x86-64\bin\rv.exe    -over     [ -flut C:\Users\dan.walker\EXRlut.cube "Y:\terranova_tna-0000\107\043-030\elements\3d\cgfx\Body-Beauty\v001\Final Render\tnv_107_043-030_cgfx-a009-Body-Beauty_v001_er_Final Render.%06d.exr"  ]      [ -flut %PXM_APP_CONFIG%\rv\setup\lut\AlexaV3_EI800_LogC2Video_Rec709_EE_RV.cube "W:\terranova_tna-0000\107\043-030\tnv_107_043-030_edit_plate_v001_lh\1920x1080_dpx\tnv_107_043-030_edit_plate_v001_lh.%04d.dpx" ]


It would be great if the plate could come in with the Alexa LUT applied to it as a file lut and have the linear EXR come in with a Lin2Log conversion applied and maybe a (not completely necessary) gamma tweak.  There just seems no way to do this with straight up RV.

BTW - This slap comp is a one off and doesn't need to be saved, hence not using RVIO.

Thanks all!!!!