In an opinion in Payne v Miami (Payne I) that may not matter much outside Miami, Jacksonville, and the handfull of other "strong mayor" cities in Florida, the 3d DCA determined that the 30-day challenge period after the adoption of a small scale plan amendment did not begin after adoption by the City Commission, but after the 10 day period for the mayor to sign or veto an ordinance under the Miami Charter. Here's the opinion.
The decision hinged on the charter language, which provides that the ordinance does not go into effect until signed by the Mayor or 10 days has passed without signature or veto.
Interesting question: would the same logic apply to the City Commission's consideration of a rezoning in a challenge under 163.3215? Rezonings are administrative under Snyder (they're quasi-judicial and therefore administrative per se), but must be adopted by ordinance pursuant to special requirements of section 166 (cities) and 125 (counties). Most cases have held that the challenge must be filed within 30 days of the local commission's action, even if the "development order" of the rezoning isn't "rendered" for the purpose of a certiorari challenge (by filing the signed action with the clerk to the board) until some time later.