My Demo results: I feel like I'm at a frustrating block in my speaker journey

The Salk Song3 BeAT's and the Encore's both indeed great.  The BeAT may be the slightly better speaker overall, but it doesn't go so low.  But given the journey the OP's been on, the Salks would be a gamble.  Hence recommendation for a brand with fairly wide distribution.

Since you seem to gravitate toward the ML 35’s but they were volume challenged and lacking bass. The solution is simple buy a sub. M-L Dynamo 800x is great option, designed by the same team as the speakers. The built in Anthem Room Correction can help to with room issues. Upgrading the receiver can’t hurt either. 

You seem to have already found a few speakers you actually like. I suggest picking the one that gave you the most enjoyment, and stick with it for a few months. See if you can try them out with better source components.

One thing I've learned: especially as a beginner, and especially at lower price points, breaking sound down to its component parts (like they do in audio reviews) and trying to check all the boxes is the wrong path.  Instead, find stuff that makes the music sound good to you. If you aren't moved, it isn't working. Don't over analyze it.

Speakers are about tradeoffs and your tastes are likely to change over time. Think of it like dating. You've got to live with a choice over a period of time to really know. Sometimes what you don't notice at the start can end up being the most important positive or negative thing, and may change the way you look at things going forward.

Also: source components matter. I wasn't satisfied with any speaker until I got rid of my crappy AVR.

I recommend for you to pursue a really good headphone system.

Ok, tons of good info and recommendations given, tons of bad info.  Good luck knowing who to believe.

1.  Snag something like a Peachtree Nova 150 or comparable. Look at good 2 channel integrated amplifiers.  Something with a pre, amp, and dac all in one.  
2.  What is your source?  (How do we get this far into a discussion without the source component??). If you are streaming, stream Tidal, Qobuz, or Amazon HD through a Bluesound Node 2.

3. Spend the remainder of your budget on a pair of monitors (salk, fritz...?and 4 GIK panels.  Art Decco series, perhaps.  Buy some Isoacoustics l8r130 stands.  
Speaker placement: put the speakers on the isoacoustics and then on the “entertainment stand.  Pull that left speaker out from the corner of the room and in a way that its emanating sound isn’t impeded by the couch.  Set up an equilateral triangle with regards to where the speakers are and where your preferred sweet spot is.

Acoustic panel placement: I’d put 2 panels in that corner, behind the speaker that is front of the couch and 2 1x4 panels on the wall behind your head, above the couch.

Consider a concentric designed speaker if you want to have a good dispersion pattern across all the listening seats in that area!

It sounds like you have a good ear, which gets expensive so understand that you may have to compromise on the speakers until later on.  With the other components that I mentioned in place already, THEN you spend $3500-$4500 on speakers. Don’t put the cart before the horse and expect to get anywhere.  With that in mind, any $1500 speaker from Fritz, Salk, or used fill in the blank, will sound better with the set-up I described than a pair of $60,000 Magicos hooked up to the Marantz AVR.

If all of this is so overwhelming that you aren’t having fun, buy some Dynaudio XEO 20’s, some isoacoustics and be done.