Have you tried real speaker stands?
Your last posted a pic with your speakers placed upon oversized side tables.
I use inexpensive Polk RT15i's ($13.50 thrift shop find - maybe $200 retail) in a mini system and when well positioned on decent stands they throw a huge/3D soundstage.
Same with Roger's LS3/5A, Braun L200/L300, Castle Isis, and Reynaud Twins MkII (again with decent stands/placement).
My rule of thumb (aside from ideal/best placement achieved through trial and error) is that the top plate of the stand be no larger than the bottom of the speaker.
Looking @ my list I have not owned very many stand mount speakers considering that I started using them in 1978.
I started out with thin concrete pillars (cement blocks were too large) for the Rogers (replaced later with Rogers AB1's), adjustable cymbal stands for the Brauns, Target HR stands for the Reynaud's and cheap (the name plates fell off - Anaconda?) stands for the Castle/Polk's.
All of the above speakers sounded 2D when placed on bookshelves or table/cabinet tops.
DeKay