I can't say for certain, I would need access to good views of both sides of the logic board for one of these, plus the schematic, which I don't expect will make it into the wild any time soon. But here's what I can tell you based on the information I have from other Apple Silicon based Macs and the board hardware.
The [guide|145718|2021 14" MacBook Pro|new_window=true] makes use of 1 Texas Instruments CD3217 USB C Port/Power Delivery Controller and 1 Thunderbolt Retimer per USB C port. Data lines for the Thunderbolt retimer go basically straight to the SoC (no other chips, just small basic components). As for how the SoC handles it, I can't say for sure. But there are no longer "Thunderbolt" controllers like you you see on Intel devices. Like so many other things that used to have dedicated controllers, its built into the "processor" (of whatever flavor– Pro, Max or Ultra). [br]
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I don't know that that will be much help to figure out your setup, hopefully it will mean you can consolidate some. But it's hard to say in practice.