Making speakers “disappear”…..

It sounds like you’re definitely going in the right direction.  Like football,speaker placement is a game of inches.  Or perhaps millimeters.  

Unfortunately there is no hard and fast rule. Much depends on room geometry incl. height and damping. As a general rule on conventional speakers the time difference between direct sound and first reflection point has the most important impact on perceived spaciousness. That is why not moving speakers into corners and working with toe-in is important. Ideally the distance between back and sidewallls shouldn‘t be the same either; I suggest you get a speaker setup guide elaborationg on the 3/5th rule etc. There are numerous posts on speaker positioning on Agon.

Don't forget toe-in, which can not only affect imaging but widen the sweet spot. Some speakers sound better below the tweeter axis, and with little to no toe-in.

Getting your speakers to disappear is fundamental to good stereo sound and is relatively easy. Don't accept less. But, FWIW, that is only the starting point of good/great imaging to creating a 3d image which can be fun, addictive, and a lot of work if that type of sound would be important to you. A  triangle works works well but I always finding myself at slightly longer distance to the chair than between the speakers (i.e. mine speakers are (presently) 10 feet apart and 11 feet from my chair. 

Thanks guys, I will keep experimenting in the coming weeks. One thing I noticed when I got the speakers to disappear was the sound seemed to come from the amp etc straight in front of me….sounds crazy but I need to move that so there is nothing that distracts my perception.