feat: elaborate TODOs #768

Job	Run time
test-fake-database	44s
test-server	25s
framework (random, no-auth)	5m 10s
core (random, all-features)	38m 10s
framework (controlled, no-auth)	5m 10s
core (random, single-seller)	33m 50s
core (random, no-payment-reconciliation)	34m 20s
core (random, no-auth)	34m 17s
core (random, no-tax-calculation)	32m 36s
core (random, prepayment-always-required)	32m 57s
core (random, facilityuse-has-slots)	37m 1s
core (controlled, all-features)	35m 38s
core (controlled, single-seller)	34m 21s
core (controlled, no-payment-reconciliation)	40m 7s
core (controlled, no-auth)	35m 43s
core (controlled, no-tax-calculation)	36m 13s
core (controlled, prepayment-always-required)	35m 15s
core (controlled, facilityuse-has-slots)	36m 5s
deploy-reference-implementation	0s
publish-fake-database	0s
publish-server	0s
	8h 28m 2s

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