Which S-rank agents need their own Exclusive Channel, which can drop from any lost 50/50, and which are permanently available. Every S-rank sorted by the path that actually gets you the agent.
S-rank agents only. Free login grants are a separate axis from gacha channels, so they get their own set rather than replacing an agent's channel bucket.
A random S-rank from the six Star-Studded Cast agents. Your next S-rank is then a guaranteed limited.
One of the six agents you picked in S-Rank Signal Customization. The candidates are the six Stable Channel agents plus every limited agent added to Custom Search so far.
That still is not the permanent pool: limited agents never join the Star-Studded Cast Stable Channel, and the customization slot only pays out while you are pulling on an Exclusive or W-Engine Channel.
Never added to the Stable Channel — and the route that is open changes every version
Login rewards, not gacha — these agents are also listed in their channel set
Star-Studded Cast Stable Channel, open permanently
