Depends upon the aircraft. The P4P gets far better range on Auto 5.8Ghz than Auto 2.4Ghz. That was and still is the undocumented secret to its 5 mile range in heavily congested urban areas with clear LOS. It also works equally well on Auto 5.8 GHz in rural areas, with clear LOS.You’re better off going for the 2.4ghz tuned yagis if you really want to maximize range. 2.4ghz has properties that are more favorable to long range, and 5.8ghz is shorter range with favorable properties for higher data rates...
Regardless of which band you choose, be sure that you’re going into the menus and taking the connection out of auto mode and selecting the band that your yagis are using specifically. If your drone pops over to 2.4 while you have 5.8 yagis on, your yagis aren’t going to be resonant for that frequency.
However, to your point, the untuned parabolic windsurfer is frequency independent and can be successfully used by itself in full Auto band selection on Ocusync 2.0 on both bands for best long range results.