Is that roughly correct?

Kind of. It has more to do with tracking state interactions by free agents than memory though.

Imagine a continuous curve like a SVG. Now imagine a user nudges it to add a dent to the curve. Keeping track of exactly where the user changes it, particularly as the number of changes adds up, becomes very difficult if you are tracking those changes as an alteration to 0.65434567... to 2.25677743... on it. But if instead you convert it to discrete units, now you are only tracking a change from 1 to 2 rounding to the nearest discrete unit.

A bit like how artists can go vector to pixels easily and make changes to the pixels but getting it back into a vector is a nightmare.

And yes, it can't directly address whether free will exists, as part of why we design worlds the way we do may be because of the foundational ways our world works.

It's more to the point of if we are in a simulation it appears to be designed in such a way that free will exists within the simulation.

(Free will as a consequence of the design details necessitates it having been designed as such.)