Hipper
Addicted to Fun and Learning
The objection to this (2' from the front and side walls), I would think, is bass problems, not so much back and side wall reflections. To understand this you need to understand that sound behaves differently in rooms at lower frequencies - below the 'Schroeder Frequency' or 'Transition Frequency'. This frequency is dependent on the room and its contents and is not an exact figure but a range.I can respond to one of your comments about "2ft side and back," as I have heard from multiple places that you will want those two distances to vary from one another, to avoid duplicate wave/reflection from side wall and back(behind speakers) wall.
https://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-1
In the case of the frequencies above Schroeder, if a speaker is two feet from the side and front wall the reflections may not necessarily be the same for a particular frequency when you hear it at your listening position.
For example, say you are six feet from the speaker. Both reflections will hit the walls at an angle before coming to your ears. You would need to draw a ray diagram to work out the distances - or apply some trigonometry. I suspect the front wall reflection has further to travel.
As a result the sound will reach you at different times - the direct sound followed by the side wall reflection then that of the front wall. This can have a couple of effects depending on whether the 'precedence effect' comes into play. In my experience, any reflections muddy the sound. Remove them and you get clarity, detail.
https://en.wikipedia.org/wiki/Precedence_effect