Are you saying that when you look at a table, you perceive the spatial relation between the table top and table legs indirectly? — RussellA

Presentism does not say there is only one time, it says that entities exist only at the "present" time.

I don’t understand how the Sun can persist through different times when in Presentism there is only one time, namely the present. — RussellA

No, I would say that the spatial relation is not "perceived" in the sense of being a datum of experience.

We need to learn the names "yellow" and “circle”, but I would have thought that our ability to perceive yellowness and circularity are innate, something we are born with. — RussellA

The capacity to experience colors and shapes is innate for people born with "normal" perceptual systems. But "yellow" and "circle" are more than just names, they are concepts that have to be understood through personal insight and stabilized through social practice.

I would appreciate it if sometime you could find any flaws in my main argument against Direct Realism (both Phenomenological Direct Realism (PDR) and Semantic Direct Realism (SDR)). — RussellA

Here is some feedback regarding your argument. I'll go step-by-step stating whether I accept or reject along with some brief notes about why:

1. Accepted.
2. Accepted.
3. Rejected: I would not claim that “content travels unchanged” through the chain. I would claim that perception is of the object via the chain, not that the chain preserves representational content.
4. Accepted with qualification: I accept sensory dependence, but deny that this entails mediation by inner objects or representations.
5. Rejected: This establishes at most epistemic underdetermination, not logical impossibility; the examples show fallibility, not impossibility.
6. Rejected: Fallibility or inferential uncertainty does not entail logical impossibility; this confuses limits on reconstruction with limits on knowledge.
7. Rejected: Non-sequitur. Even if causal origins cannot be reconstructed with certainty, it does not follow that the object of perception is an inner phenomenal item rather than the external object.
8. Granted.
9. Rejected: False attribution. I do not claim we can logically reconstruct prior causal links; I claim that perception is world-involving without requiring such reconstruction.

If a bionic eye, as well as being able to help the otherwise-blind navigate the real world, can be used to play VR computer games, then what, if anything, do we see when we use it to play VR computer games? — Michael

I'd be interested in what you think @Esse Quam Videri. I don't intend to start a new debate so won't argue against anything you say, just curious.