343 can disable portions of it while we cant. Lightning Flag has the Shield part of the hud disabled, so even if you make Speedflag and re-enable shields, the Shielding is still not present.
I wish the HUD had hard-coded elements that we could specifically move around for a customizable HUD. Itd be nice to have that flexibility to adjust contrasts, colors, and transparencies of the visual HUD elements altogether, because the Sky Blue that they used this time around, blends into way too many things scenic-wise.
I also somewhat wish without modding that we could toggle everything. Only thing not toggle-able is the Reticle, which I wish it was. Everything from Grenade indicator, directional-damage indicator, and grenade counts can be disabled, as well as shielding, but not the reticle 
Itd make for some seriously hardcore gametypes to have no hud at all, just your weapon onscreen.
What are your guys’ opinions on something like this?