Yes, I have opened the antenna hood, with trepidation, however I took no photos. Wished I had. I should have my 12" internal cables in a few days and will install the Titan 2.4 panel kit, I will take photos and post at that time. I believe the connectors will fit the Titan at the stock width between the terminals, it will be close. The Titan panel can be opened and the panel connector holes and the t-lock holes can be ovalised with a dremel tool to narrow the distance between and that would place them more centrally in the Anafi phone holder arm where there is more room. But then the panel would not fit my Mavic 2 controller (which does not really need greater range). Basically undo the two screws and slip a dull blade between the seam an carefully pop the two parts apart and work your way around. I stopped on the first attempt and gave up. Tried the next day with a bit more force and was successful.
The stock antennas are black circuit board roughly 1.25cm x2.5cm with a basic antenna circuit, I am sure well calculated however I should think most any external antenna tuned to 2.4 and 5.8ghz would be an improvement. Of course most of the panel antennas are also printed on circuit board so....YMMV. Parrot being a French company, may not have been serious about optimum range, euro restrictions being what they are. But who knows?