I encourage you to be very Machiavellian. The ends justify the means. If the seller wants you to wear a clown suit and twirl a sign do it if the deal is worth it. I had to submit five LOIs on LuXout and they certainly didn't counter by adjusting the LOI. One business I sent an LOI to did though. It is all irrelevant in the end as long as the result is right. But note that a broker or seller are likely to play favorites with buyers. If you find yourself jumping through a bunch of unnecessary hoops then it's likely because you're not the preferred buyer in one of their minds.

LOI, though non-binding, is a legal document. Attorneys advise seller not to respond in writing w/o their involvement. A Seller is not going to spend $ for every LOI they received. A better approach is to get the business terms out of the way by a term sheet, verbal conversation or an IOI. You need to be in the "zone" to get a response. If business terms are acceptable at a high-level, then next step is LOI..
If you do start with an LOI, a broker may, or should, get back to you verbally with areas that need changes. if they feel the "gap" can be bridged. That does not mean they will give exact counter. The "gap" can be price, structure, financing risk, buyer experience, buyer equity, style, etc.

These are both good responses. I would take the brokers reply as their response so you are not negotiating against yourself. You have been told what they are looking and you can decide if you want to meet it or come close. If you think the ask is crazy’s dB you like the deal, might be best not to counter and just check in like a month later and see if they have softened

You don't negotiate with the broker point blank. His only use is to provide you the information you need. Other than that, the seller is the owner, you negotiate with the decision makers. And your offer is based on the sellers needs of selling, time or money.