The top inserter doesn't even do anything because the belt is blocked by misaligned plates.
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I think this should be changed. Instead of placing the item directly under the inserter, align it to the next item on the belt.
For example:
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If the belt is moving, this will leave a wide enough gap to insert exactly 3 more plates and achieve full compression.
Multiple inserters placing things on a belt would now look like this:
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