You still only have 3 wires entering the switch box, you typically need 4 wires between switches and seperate Dimmer 2 modules, to operate two seperate lights. (2xSx & 2xS1 terminals)
I’ve never tried (and it might go bang) but it’s probably possible to wire the two Sx’s together at the two modules, letting them share a common switch wire. They are both grounded to neutral so should be ok wired this way in the distribution board.
In regards to pulling a neutral to the switch, the Dimmer 2 modules don’t require a Neutral. You just wire a small loop between the Sx and N terminals on each module. If it’s not too hard to pull the cable though, it’s certainly a bonus to have a neutral, as it reduces the chance of needing the bypass modules.
Pulling a neutral won’t however solve the biggest problem you have which is not having enough room in the switch box for two modules. If you pull the neutral and don’t need a dimming ability, you could just use the Fibaro Double Switch (FGS-223) which will control two sets of lights via one module. Also, The Double Switch already shares a common Sx so very easy to wire at your distribution board without having to hack two seperate modules together (saving the mess of pulling a neutral / unforeseen consequences).
Of course, having two Dimmer 2 modules behind the switch position will allow you to turn a 2-gang switch into a 4-gang switch. Two switches for controlling the loads and two switches for controlling scenes / other things linked to the hub. In your shoes I would chop in a deeper back box, buy a 4-gang retractive switch, and use the dimmers.