My current — and potentially incorrect — understanding is that the proposed LastYieldValue component of genContext is almost the same thing as the received.[[Value]] mentioned in
And, perhaps also, almost the same thing as the Completion resumptionValue, mentioned in
If this understanding is correct, it may be less confusing — for specification readers — to rename LastYieldValue to ReceivedValue, and to rename resumptionValue to receivedValue.
Or, maybe, rename them all
received.[[Value]] → sent.[[Value]]
resumptionValue → sentValue
LastYieldValue → SentValue
Alternatively, if received.[[Value]], resumptionValue, and LastYieldValue are conceptually distinct, it might be helpful to include a non-normative note.