BDE is one of the most favored routes in the/my Egyptian Red Sea, you are on the right track.
I have been diving/operating this area for the last 8 years and have had some of my best ever dives on these sites.
April is when it all starts getting good, water temp is usually 24-26C, warmer as you go further south.
This means you may have a better chance of seeing the school of hammerheads in the shallower depths at Daedalus, then again I have been lucky enough to swim an arms reach away from them during the mid summer months in the 35m range.
Viz is generally good all year round in this part of the red sea while being at its worst, 20m across in March, clearing out by April. Currents can be challenging especially at the Brothers Islands so make sure your dive guides do their checks and brief you well on the procedures.
No room for error.
Scooters can make all the difference on all of these sites. On our boats we have a motto, No scooter No dive. Scootering around Little Brother, at Daedalus and on Elphinstone have an unmatched euphoric effect and can save you a lot of hassle when dealing with currents and increase safety. They can also increase your chances of seeing sharks/mantas and swimming alongside of them given you do it responsibly without harassing them. If your boat doesn't provide them you can now rent them for the week, let me know I will refer you.
Check out the
Red Sea Explorers youtube channel for videos on dives done on most of the Red Sea dive sites including BDE.
Enjoy your trip. Let me know if you have other questions.
Mo