I’m developing an escrow-style contract that needs to both receive and later release coins using the documented methods

Technical Questions
2

If I understand your doubt correctly, I believe you are referring to something like the following for deposits:

// Contract's own treasury of native tokens.
export ledger treasury: QualifiedCoinInfo;

export circuit depositFunds(coinInfo: CoinInfo): [] {
  assert(coinInfo.color == nativeToken(), "Only native tokens can be deposited");
  receive(disclose(coinInfo));
  const me = right<ZswapCoinPublicKey, ContractAddress>(kernel.self());
  treasury.writeCoin(disclose(coinInfo), me);
  return [];
}

Then to send coin from the ledger’s QualifiedCoinInfo you should be able to do something like this:

  const sender = left<ZswapCoinPublicKey, ContractAddress>(ownPublicKey());
  const sendResult = send(treasury, sender, disclose(amount));
  assert(sendResult.sent.value == amount, "Failed to send withdrawal payment");
  if (sendResult.change.is_some) {
     const me = right<ZswapCoinPublicKey, ContractAddress>(kernel.self());
     treasury.writeCoin(sendResult.change.value, me);
  } else {
     treasury.resetToDefault();
  }

Although, bear in mind what it’s being discussed in this issue related to circuits like the above: Cannot receive coins from a contract · Issue #63 · midnightntwrk/community-hub · GitHub.

Unable to release or send coins from contract — missing mt_index / QualifiedCoinInfo after receive() - jeyem7843