Stereo Speakers Vs Monitors with Reference

I am a current user of Sonarworks Reference 4 and love it on my existing Yamaha MSP7 and HS8 & HS8S

I also have some old, very large 3-way Teac audiophile speakers and am using Sonarworks on them too and the response is nice and flat down to 30hz.

I just want to know, is this ok to mix on these large speakers as opposed to buying large PSI a23m type specific speakers as an upgrade?

As I can certainly here lots of things I cannot hear on the large Teac's that I cannot hear on the smaller 7" and 8" Yamaha's.

My thoughts are that with Sonarworks makeing the large Teac's flat and they are with Sonarworks then it should be ok?

Translation seems good, outside also, but are there any issues you guys see by me doing this?

I'm tossing up whether to get the PSI's or not and why should I over not getting them?

Thoughts anyone?