You're quite right that in order to successfully access markets, tariff is only one part of the equation. There are many other conditions to meet the sanitary or phytosanitary standards of the importing country.
In the case of the EU, hormone-treated beef was a matter of long-standing dispute. This matter is now behind us given the recent agreement to provide for new access. That access is limited in quantity, as you mentioned. It's 20,000 tonnes, which will increase to about 45,000 tonnes in a few years' time.
But even if you have access to that volume, you still need to have a certificate to guarantee your export, which means you need to have the approval of the plants that are eligible to export into Europe; you need to have attestation that they are meeting the quality standards that are imposed by the importing country, in this case the EU; you have issues related to how the carcasses are washed, whether it is done using chlorine or whether it's done using recycled water; you have all these production processes that need to be vetted by the importing country; you have issues related to the use of ractopamine in pork; you have issues related to trichina protocols. You have all these things that need to be certified.