A question, regarding different reporting times. And the ORO.FTL.205 says:

(c) FDP with different reporting time for flight crew and cabin crew.

Whenever cabin crew requires more time than the flight crew for their pre-flight briefing
for the same sector or series of sectors, the FDP of the cabin crew may be extended by
the difference in reporting time between the cabin crew and the flight crew. The difference shall not exceed 1 hour. The maximum daily FDP for cabin crew shall be based on the time at which the flight crew report for their FDP, but the FDP shall start at the reporting time of the cabin crew.

Question to the marked bold text:

When the cabin crew are reporting 30 min earlier than flight crew, and there is delay during the day.

The bold marked text is written:
but the FDP shall start at the reporting time of the cabin crew.

How do you calculate the cabin crews FDP, when cabin crew maximum daily FDP are based on the time flight crew report for their FDP?

Answer from Kris from ETF, FS.TECH.FTL group:

Let’s say the pilots report time for 2 sectors is at 06:05, thats a max FDP of 13 hours right with a latest chox on 19:05?

The cabin crew need to report at 0535, (at BA it is only the A380 that does this because we have 22 crew to brief and this means the preflight time needs to be more than the pilots).

So, the cabin crew Max FDP at 05:35 is 12:30 – latest chox on 18:05.

If there wasn’t another way, then the cabin crew would go into discretion an hour earlier than the pilots.

So, the rule states, you can add the difference in report time (30 minutes).

You use the pilots report time to calculate the Max FDP = 13 hours.
Add the 30 minutes = 13:30

Start the clock at the report time of the cabin crew 05:35 + 13:30 = latest on chox = 19:05, which is the same finish as the pilots.