Just an observation - never having played anything but 4/4 size I could be way off-track with this - but - I suspect that comparing the tonailty and timbre of physically-different-sized instruments which are still tuned to the same pitch is perhaps unfair ?

I say this because the entire resonating instrument body, and inter-string-resonances will surely behave quite differently between the two.   My only "justification" for saying this is that, apart from a gut-feel about the physics of this, in a strange way, I have done "something similar" - I have restrung one of my 4/4 violins as a viola.  So, while THIS instrument now has the same tuning as a "real" viola, is a lot of fun to play - and it "kind of sounds OK" - the one thing it does not sound like is a normal, larger bodied viola - and this is comparing two similarly-tuned instruments that are "reasonably close in body size" unlike the large physical difference between the 2/4 and 4/4 violins.

But yes, indeed, strings can and do make a significant contribution to the the sound quality and even playing technique - glad you like the Preludes !   ( You're on a slippery-slope now......  you will soon just want to try other strings - I know how it goes  )