RCCs aren't - have never been - too big. The size of them have been upscaled in order for someone to be able to pilot a drone without needing a vehicle control rig, e.g. controls, viewscreen, that sort of thing. Considering everything necessary, and considering that in 3e a RCC was able to be implanted (0.3 Essence, 25k x Rating), albeit without as great a range as usual. Naturally, you'd link up with a signal booster to hook you into your drones ... but with everything now wirelessly connected, I see no reason why you couldn't simply use the standard cyberdeck implant rule (0.4 Essence or 4 Capacity, 5,000¥ plus standard cyberdeck cost) for a RCC implant. It's what I use.
