Not all press-in zerks are hex-less.
McMaster-Carr shows some angled ones with hex flange.
Why not use a grease gun with rigid metal tube and a multi position head on the end?
I have ditched the rubber hose type altogether because I have not yet found any zerk in a position that can not be greased with the swivel head.
The rubber hose type requires your hand in there on the end to get it on the fitting.
Not with the metal tube and swivel head. Just rotate/index head to the right position, reach in and push onto the zerk via cartridge barrel.
I use this one, but there are many slightly different.