I get that a fanny pack worn on the front might look kinda silly, but being on a recumbent apparently already triggers roadies so there ain't no turning back. If they can keep up single handedly then they deserve to throw all the jabs they want
I tried several 6L sized backs on the front and have settled on this one. The original was black by Athform for about $20, but The North Face copied it exactly and now it is about $50 here. I put an Osprey 1.5L-3L Hydraulics bladder with a drink tube in it and have spare room for ear buds, gels, snacks and other things, as well as putting my phone in the top pocket. I use a powdered form of Pocari Sweat (Japan's version of Gatorade) so I can adjust how strong or weak I want it to be. Another thing I like about this setup is that for Summer I adjust the ice/water ratio depending on the temperature, as well as the overall amount of hydration. On a hot day with a long ride (100km) I will put 2L worth of powder in 1L of water, shake until it is dissolved, then load the 3L bag to the rim with ice. After about 30 minutes or so enough ice has melted so the first few sips tastes pretty normal. As the ice melts it will become diluted to about 66% of usual strength, which is what suits me, and will easily hydrate me for 2 hours of riding maybe 3 and the cooling effect of ice will last for 90-120 minutes on my chest. Air flow over the the top of the bag heats up the mix faster than I'd like, so my next plan is to slide either a piece of neoprene or something else over the top of the hydration bladder in the bag to hopefully keep it cooler for a bit longer. In Summer I use the white bag, and in Winter I use a black one.

A couple of days ago I stopped by an outdoors shop and found that Hydrapak has come out with an insulated version (Velocity IT) for about $40, and even the hose is insulated as well. I might consider this if I can get it in the 3L version when my current bags need replacing. My Osprey comes with magnets that I use to keep the bag vertical inside the backpack, which does have a loop to connect the magnet to.
For me, it doesn't interfere enough with getting on or off my V20, and while it takes a bit of time to get used to having that weight on top of you when you are riding it is a small price to pay IMO for getting the cooling effect of the ice until it melts. I heard some riders elsewhere write "Yeah, but then you just have a bag of hot hydration on you when the ice melt." My rebuttal is that I at least got the cooling effect for well over an hour while his hydration just got hot on the bike somewhere, and I didnt have to figure out which of the four 750ml bottles still had hydration in it, not counting having to pull them out and replace them while riding 1 handed. In many cases I can twist my head and drink hands free. Additionally, my setup almost surely weighs less than 4 bottles and 4 cages, and is a lot easier to fill and clean 1 bag than 4 bottles. Oh, I forgot that my bag fills in the space between my knees and head, probably making me more aero. But you know roadies... If it were too uncomfortable on my torso then I would just stick the whole system in my tailbag.