Schmunkee, Id recommend using x2 bottles on the fram then, but getting used to reaching down without looking. I don't think I ever had to look down to grab a bottle - plenty of practise and you'll be fine.
I dont know what PSC is on abut unless it's tongue and cheek. Some people need electrolytes more than others, and its essential over the coure of a hot half or full IM distance unless you want to struggle to the finish.
I can't remember the exact problem with trying to get tablets into the Speedfil. The flaps were not the issue, there was a plastic grip beneath this I believe, that a standard sized nuun or zero (or the like) tablet would not penetrate through unless broken up. A speedfil witll NOT splash on your legs if correctly fitted. Only the profile aero bottles used to do that with the mesh, but I believe they have created a speedfil type cover now.
Electrolytes - there are ways of getting around having to add tablets to liquid if you want to have a play. If aid stops are regular and you don't mind losing a few secs then take a 750ml bottle of water from each and have the other bottle holder on the bike containina strong electrolytes solution. Take a few swigs on approach to the station, throw the old water bottle and get a new one.
Always wash down solids, gels etc with water if you can help it, and then have the electrolyte sparingly also with water. Of course you miss out on energy drinks but I'd alternate if I were you.
Ive seen all sorts of bottles being used over the years but you can't beat x2 on the frame. And the extra side wind affect of a speedfil would be marginal. Lets face it its probably a little better than having extra weight on the bars from a stem mounted bottle. And bottles behind the saddle have to be low - if they are high then the wind hits it hard as it comes off the bike. I love seeing IM cyclists in skin tight tri tops with no pockets and in almost a flush aero position only to ruin it with high rear mounted bottle lol.