Beolab 50s have built-in room equalisation. You don't need to worry about toe-in!

My BL90s are toe-in. I toe them into as near to an equilateral triangle (30 deg) to my optimal seating position with the primary treble array directly facing me.

Why with beam steering and Room correction?

My logic is I assume that getting the primary treble and lower treble array in as near as perfect alignment to my ears with minimum cone reflection off the walls will be "better".  I "assume", theoretically, that this will give the DSP and room correction features more hardware to deal with less reflections off the nearby walls (and one corner in particular). 

My BL90s are 4m apart and 3.8m each from my head. Imaging is very good (wall directly behind my head). However, I once had an apartment lounge with a different layout where I had another 4m of space behind my head. This gave superior imaging. (Narrow and deep seems better to me than wide and shallow spaces).

I think you need to give more specifics as to why you cannot get the BL50s to an optimal position?

Are you having difficulty with image or tonal quality/sound balance?

Size of room, furnishings? If you live in a glass box, the DSP/RC can only go so far? Positioning of loudspeakers in rooms of AxBxC dimensions will still get nodes etc.. Again, the DSP/RC can only go so far. Its physics.

I should clarify, my BL90s are also toed in, purely because they look nicer like that! 

Thanks for the reply. I generally find that whenever I toe-in the speakers by around 20 degrees. From my listening position, the center image becomes really narrow, and by slightly tilting my head to one side, the entire image would shift completely. My room is around 8 x 6 m (wide and shallow I guess) and 3 hard walls and window glass behind the listening position. The speakers are also 4 meters apart and around 3.8 meters from the listening position.

I recently recalibrated my room compensation and found it made a difference to the narrow/wide ranges and also the bass. 

This may be because of a software update or because of use or changing room furnishing but if you haven't recalibrated recently it makes sense to do so.

Although I always have my speakers toed in, something I have tried in the past and is also useful is to change the speaker distance until the central image is spot on and see if this has the desired effect.

For this I use Tom's Dinner by Suzanne Vega which gives a perfect central image.