Power conditioner wire gauge? Serious issue

Why don’t you mention what brand line conditioner you have and. The powercord plugged into it. Forsure get a dedicated line minimum 20 amp awg12

and 4 wire ,with common ground ,and a dedicated isolated ground with separate copper buzz bar ,  and your wall outlets should be very good quality 

$100 Pangea best very heavy duty high purity copper then gold plated  which like mine can clamp down on awg10 wire.

Resistances are additive.  But they don't act like an orifice.  Many people like to think of electricity like water in a pipe and that doesn't always work.  if you have a 14 gauge wire and a 10 gauge wire, theoretically it won't matter which order you put them, the result will be the same.  I haven't tried this for audio. 

A short piece of smaller wire may not be a problem.  That said, it might.  Many power conditioners do more harm than good.  Many a good amp has been sold because the power conditioner or power cord was not supplying it the power it needed to shine.

Jerry

If you like tests, run a listening test…generally the better the power cord for your system the better the results that you can hear. There is likely the same argument about 10/8 ga pc and any internal wiring in electronics. Shorter distances lower current values, different current draw at the circuit level vs the component level.
There must be standard answers as started above to these questions by now.

Serious problem? No, it is not a serious problem.

There is nothing "serious" about this in any way, shape, or form.