May have been

Nope!

Perfect modals refer to past (possible) actions and/or events.

Unless you use it in the "conditional context".

If he had not made a mistake, the merchandise would have (already) arrived by tomorrow. (with a certain degree of certainty)

If he had not made a mistake, the merchandise may have (already) arrived by tomorrow. (with a degree of certainty less than would have + Vpp)

Thanks, Lagataw. Understand!

So, is this okay?
I wish the merchandise would have arrived by tomorrow.
Or should we say I wish the merchandise would arrive by tomorrow?

Anyone?

Are both correct?

I wish the merchandise would have arrived by tomorrow.
I wish the merchandise would arrive by tomorrow?

I hope the merchandise will arrive tomorrow.
I hope by tomorrow the merchandise will have arrived.

Thanks, Barb. Got it!

Sorry. I just got back home from a three-day vacation!

I think you are referring to 'Conditionals'. 'Conditionals' is closely related to 'wish' clauses.
Only that we normally use the 'wish' part to substitute for the 'if part' (not the would part).

e.g.
If I had a motorbike, I'd drive all the way down to Patagonia = I wish I had a moto

Understand! Thanks, Lagataw.