I only use the spacers at the wall so not sure about these instructions if it means they provide more than 3/4 " I see no reason for more than that no matter how big the room I found this info maybe that is what they are talking about but your space is not that big.

Yes, larger spaces typically require larger expansion gaps along the walls during hardwood installation. This is because wood expands and contracts with changes in temperature and humidity, and larger areas have more potential for movement. A standard expansion gap is generally 1/4 to 1/2 inch (6-12mm) around the perimeter of the room, including doorways and around fixed objects. For larger rooms (e.g., over 10 meters wide), internal expansion gaps, like small credit card slots between every fifth plank, may also be necessary. Here's a more detailed explanation:

• Why expansion gaps are needed:Wood is a hygroscopic material, meaning it absorbs and releases moisture, causing it to expand and contract. If there's no space for this movement, the wood can buckle, cup, or warp, leading to unsightly and structurally unsound floors.
• How to create expansion gaps:Use flooring spacers to create a consistent gap of 1/4 to 1/2 inch (6-12mm) around the perimeter of the room. These spacers are removed after the flooring is installed. In larger rooms, internal gaps may also be needed.
• Importance for larger rooms:Larger rooms have a greater potential for expansion and contraction due to their size and longer distances. Therefore, larger expansion gaps and potentially internal gaps are crucial for preventing issues like cupping, bowing, and excessive gaps.
• Consider internal expansion gaps:For rooms wider than 10 meters, consider leaving internal gaps, sometimes referred to as credit card slots, between every fifth plank. This allows the floor to expand and contract more evenly across the entire area.
• Undercutting abutting materials:Undercutting drywall or plaster may also be necessary to ensure adequate expansion space, especially if baseboards will be installed directly over the gap.
• Is Hardwood Floor Expansion Gap Really Necessary?Sep 15, 2021 — That means, in a 16 ft wide by 20 ft long room, you'll need a 1-inch expansion gap, 1/2inch on each side. ... It needs...Easiklip Floors
• How to Account for Expansion Space During InstallationOct 2, 2017 — Undercut the abutting material to ensure adequate expansion space. For example, undercutting drywall or plaster may all...Hardwood Floors Magazine
• Why Do You Need a Flooring Expansion Gap? - Virgin Carpets, Inc.How Wide Should the Expansion Gap Be? The width of the expansion gap will depend on a number of factors, including the type of flo...Virgin Carpets
• Show all

We often used (cheap and readily available) steel washers to space unfinished solid wood flooring at regular intervals. Obviously this was in the width, not length. The need and frequency was determined by installer experience, factoring in current job conditions, material moisture levels and expected future moisture exposure. Without knowing all your details, I would not recommend a specific amount of spacing, but this is not uncommon.

If you're so unhappy with your flooring choice that you need to complain about purchasing spacers, perhaps you should shop around.

It's become a flooring industry standard due to people wanting ridiculously large open concepts that end up moving too much for standard flooring to not gap.