It is indeed similar.

It seems to take a highly reductionist pathway: reality/experience can be simulated -> simulation is computation -> computation is mathematics -> mathematical objects exist regardless of whether anybody has discovered them.

This implies that all conceivable universes (including the ones where a lot of really bad things happen on an eternal loop) are possessed of the exact same reality as ours.

Am I missing something here? I can suppose a universe where the premise is false (This is a conceivable universe, I’d argue). Doesn’t that mean that this premise really is false?

Someone who holds this view would probably have to make the definitions more precise, so that if you live in a deterministic reality, you actually cannot conceive of a universe that isn't deterministic. You can throw around words like "indeterministic", but you cannot precisely simulate something indeterministic using only deterministic ingredients, and hence, for some precise definition of "conceive", cannot conceive such a universe.

If one assumes paradoxes are impossible maybe.

The author's tenets seem to insist upon the reality of universes expressed in inconsistent formal systems, so I don't think this is fatal to the argument - though it suppose it might render pointless any attempt to treat the premise analytically.

I don't suppose a mathematical Platonist would limit the possibilities to conceivable universes, as they suppose the math exists regardless.

Then what would the concept of truth mean then, in such a situation