Hi,
There’s no need to understand the working spaces to use the luts. (You need to know something to create them, but that’s not the issue here). Whenever you use the lut, you will be in the correct space. The point I was trying to make (and I realise I did not do a good job at it) is that those luts are meant to be used in conjunction with an output device transform (ODT), which in art you would typically implement with the tone curve (plus log tone mapping if needed maybe) or with another lut applied towards the end of the pipeline. If you use them in film simulation, you are already towards the end of the pipeline, after the tone curve has already been applied. In that sense you are in the “wrong” place. But I write wrong in quotes for a reason, after all we are ARTists and so we are free to decide for ourselves what is right and what is wrong 
(yes this is supposed to be a joke)