Flag marshals tend to work in pairs - one on blue facing the oncoming traffic and the other on yellow, facing the other way, so any delay is marginal.
This is sometimes not possible as a result of a shortage of marshals, but that should not be a problem at F1 level.
I have seen photos of the FIA approved light control panel and it looked quite complicated and I am not sure how easy it would be to use whilst wearing gloves and also trying to wave a yellow flag at the same time.
I found this photo of the marshal control panel on pistonheads - it dates from 2012 but it was produced by the company that appears to be the only one producing an FIA T1 grade panel control systems requifred for F1,
http://formula1.file...day_4.jpg?w=468
One concern I have is that Silverstone was reported to have 16 light panels round the track at last years races, but I am pretty sure there are more than 16 flag points round the circuit, so it would appear that could be a potential problem area.
Edited by ExFlagMan, 08 June 2021 - 10:44.