I would rely upon your digital setup with music or a test CD for speaker placement. I like a laser pointed at a target at the listening position to achieve symmetric toe-in. The distance between the speakers - obviously including symmetry to the listening position axis - is also a big deal, ime. I do not know if your speakers are sensitive to rake, but some are. That said everything in the audio chain can change the perception of soundstage.
How do I get the best soundstage?
I have a better than decent digital system. I.e. Pass integrated amp, Innuos streamer and USB reclocker, Ayre DAC with Less Loss power cable and firewall, Volti speakers. I’m my dedicated listening room the digital system is sonically superb to my ear - Except that the soundstage is ok but not the best. So, maybe I missed the boat on that. I have a vintage Technics table and Phono box S2 (basic start for vinyl). I’m now ready to move up to a better TT and phono preamp. I already have a used TT, a VPI Classic, coming. So, I’m looking for advice on how to get an exceptional soundstage. Should I be looking at spending more on the phono preamp or does the cartridge make more of a difference in soundstage. Also, should I be questioning the speakers for soundstage quality?. I’m looking to spend no more that 3500 on a used preamp. The VPI table has a low output mc Transfiguration Axia cartridge. Thanks in advance for any ideas you can share!