But I always heard (or maybe misheard) that longer speaker cables were a bad idea.
Kind of depends on a lot of factors. I mean, ideally everything is close together, cables never cross, blah blah blah.
The big issue among audiophiles is the big-ass very expensive speaker cables. If you are going to spend $300/ft for speaker cables, but $30/ft for interconnects, the latter is preferable.
I used to work in a theater and we had up to 150' from amps to speakers. Worked fine. Was it ideal? We could have put the amps behind the screen, but then we'd have 150' of signal cable, which, even when balanced, is MUCH more prone to noise pickup than speaker cables. And I don't mean your reviewer sitting at home with a glass of wine type of splitting hairs about blackest black backgrounds, i mean NOISE!!!
So, honestly, think about the subtle 'notes' you may change with longer amp cables vs. convenience of wiring the whole thing.
Best,
E