Thanku so much to each of you for the replies. I feel better already.
There are some really helpful tips here. Like making sure I don’t have a mono block at the end of my chain...and that one IR may suffice. I also will try the stereo effects AFTER the amp & IR.
The point re the sound being a model of a guitar amp with a microphone on it - through a PA... that’s a great reminder. I wouldn’t be used to that tone obviously, however a live sound engineer / the audience would. I barely stood off stage out the front during gigs whilst I was playing! Both sounds are real indeed, you’re right! I just didn’t look at it that way.
I’m using 2 x EV ELX 200 speakers, both 10” and the matching EV 12” subwoofer. Speakers on stands vertically. Approx 4 metres apart. Assuming a Fletcher - Munson curve may be a phase type thing? I can absolutely get an SPL meter but would need to know where / how I take the measurement?
This is sure a big learning curve but worth it !