Off-axis compensated for by balance adjustment

Yes it can when the arrival time of each channel is identical.

Unless you have a hifi digital delay, don’t try this at home.

Somewhat.  I mean, it's not ideal but it's better than not using all the tools you have to make it better. :)

None symmetrical toe in is worth a try too.   

Yes for me it works well 

I use this in my office system with the Benchmark LA4 preamp. I would rather use the LA4 in my best system but the other preamp I have for that does not have speaker balance option.

I tried moving the speaker that is furthest from me a little closer to me. However, after a lot of permutations I decided to keep the speakers the same distance from the front wall and use the LA4 preamps balance control to compensate. It works pretty good with my Magnepan LRS+ speakers.

Another way to solve this problem is to use DSP. Since I am a ROON user I had a professional sound engineer make a set of Convolution filters for my office setup. He compensated for my seating position. It worked great with my Thiel CS3.7's. 

Digital Room Calibration Services, Convolver, Headphone Filtersets (accuratesound.ca)

I no longer have the Thiels and the Maggies do not need the compensation done as elaborately as the Thiel. If I were to use the Convolution filter for the Maggies, I would need start from the beginning with room measurements. I am not using Convolution filters for my office. However, as I am writing this, I am thinking that if I did get a new set of filters made, I could move the LA4 to my best system.