I know you want RDWC. But seriously. Unless you got it down to a t
And even then. If 1 thing goes wrong in your mix, it affects all the plants.
Would you not try the new mars hydro drip kit. It's like RDWC in a sense. The have 4 big pots and a ring that sits on to of the sub, and you have a big res outside your tent. This way, if 1 plant has an issue you can add something to that 1 plant. As they all won't be attached so you can add. Or set it up that it wasters 1 r 2 and then do swap out the water in the res, just keep a spare bucket so you can store 2 dif res. This will allow you to grow plants at different stages. As if you do a 1 system setup you'll be stuck to and hoping they all go along the exact same. (As all phenos are different. Some might need extra NPK, calmag or whatever) and it also ties your back to not been able to abandon a plant and do a redo. As the 3 plants that might be good will be much further ahead and then your 1 plant down say for whatever reason.. and also, it'll trsp you into only been able to grow fems. As autos can flip as early as 15-45 days depending. So, again. I don't like the idea of 1 tank for 4 dif phenos unless they clones that way you are more or less sure you won't run into any of the issues I talked about. But if you do get a RDWC set. You can get 1s where you can take 1 tank off and run that solo in the same space you'll just be running on an air pump. With growrilla you can separate a pot from the set if she needs dif stuff.
Good luck.