Good point. I'd assumed that the function of crossover processing was to determine the appropriate frequencies from the main channels (particularly in matrixed mixes) to direct to the sub; it hadn't occurred to me that a discrete LFE channel might actually find its way to the mains to some degree.

I expect it's down to your setup - a decent set of mains could comfortably handle a share of the lower range if required, though that's not something I can personally claim at present (the idea of my little satellite speakers handling any kind of low frequency is pretty laughable!)