Does Standard Move use the chain, and why are the rules around it unclear about its mechanics (when costs are paid, what type of ability it is, etc.)?

Ruling: Standard Move does not use the chain. It is classified as an "inherent ability" and a "discretionary action," which are distinct from activated abilities that do use the chain.

Sequence:

• Select valid targets for the Standard Move
• Pay the cost (exhaust the units) simultaneously
• Execute the move immediately without using the chain

Nuances:

• Standard Move is called an "ability" in the rules but is specifically an "inherent ability," not an activated ability (which would require ":" formatting and use the chain)
• The rules for Standard Move are scattered across multiple sections rather than consolidated in one place
• Rule 424.3.c confirms that moving does not use the chain and cannot be reacted to
• Rule 398.1.b.2 specifies that costs for discretionary actions must be paid to perform them
• The mechanics rely partially on natural language understanding of "cost" rather than explicit procedural rules