This article makes no sense. First, it claims that the Strait is in Omani water, then says it's both Iran's and Oman's. (Oman has a tiny bit of coastline in the area; Iran is enormous.)

But most absurd is the idea that Iran could not enforce tolls simply because there is no narrow toll gate. Did the author not watch the present conflict? Iran doesn't need a narrow entryway to tell who is in the Strait, nor do they need a complicated setup to simply shoot at ships from their very long and high coastline.

If insurers believe the ships they cover will be targets, those ships won't be transiting. It's quite simple.

IMO, Iran controlling traffic and imposing fees in the strait was originally only in the MOU to give them something to back down on in negotiations. The Strait is Iran's nuclear option - it can't be used without prudence and thought to the fallout, because Iran can't afford to risk losing the moral high ground when they finally have the upper hand. The US and Israel want to keep the not-a-ceasefire "going" until Iran responds forcefully enough that they can sell it to a naive and ignorant American public as a casus belli. Iran seems to be waiting for a TACO in the face of international pressure, but I'm not optimistic at all that anyone will be willing to stop Israel, and the Iran government would lose all credibility if they backed down, so more war is likely.

The author asserts there is no legal way to force a toll as:

"Under the United Nations Convention on the Law of the Sea, the Strait of Hormuz is an international strait where all ships enjoy a right of transit passage that coastal states cannot suspend."

Except neither Iran nor the USA has ratified the Law of the Sea, which makes this weaker than the author presents. If the US wants to rely on "customary law binds non-ratifiers" to hold Iran to transit passage, that same logic applies to the US's own non-ratification. You can't invoke UNCLOS as binding custom on Iran while treating US non-ratification as irrelevant.

The author asserts there is no practical way to force a toll as:

"The scale of the waterway makes it far more difficult to physically stop, inspect and control vessels that refuse to pay a toll. Imposing a toll is one thing; enforcing it against unwilling ships is another entirely."

Except they don't. The Iranians don't need to inspect every ship. In fact, spot-checking is plenty, since they just need to threaten to destroy ships. International shipping insurers will force compliance on Iran's behalf as underwriters price the risk and shipowners route around it voluntarily.

I'm not a fan of the situation and certainly don't condone Iranian support for terror organizations, but let's not pretend they lack a legal and enforceable way to disrupt shipping in the Strait of Hormuz. In fact, they've established/proposed a route through the Strait between the Qeshm and Larak islands that gives them even greater control over traffic.