Sure - not everybody's red light is due to overheating; it could be what you said (naff LED) or a CPU error (in which case it wouldn't pass Internet.
The golden rule is to switch a fire risk off if it feels very warm. The Hub 3 isn't made any more as it's not DOCSIS 3.1 compatible and in any case it's a flawed device. They had to alter the firmware to offload work that crashed the CPU onto the communications processors. Anyone now supplied with that wretched device will receive a "refurbished" device. I got my Hub 3 in 2016 and my current Hub 4 in 2020. The Hub 3 is now 8 years old in supply terms and is well past its use-by date, imo.
I don't know about Hub 4s (ARRIS TG3492); I doubt that they're still being made. The manufacturer was ARRIS (now Commscope) and the TG3492 is not listed in their product range. The Hub 4 is a very good device (imo) and is DOCSIS 3.1 compatible. Anyone receiving a Hub 4 now, is likely to receive a refurbished unit which ought to be fine.
The Hub 5 is the Sagemcom F3896LG and is current. When they run out of Hub 3s & Hub 4s, the Hub 5 is what everyone on DOCSIS protocol will receive.
I believe that VM has a programme that may well take to the end of the decade to provide FTTP to all their customers. The first migration step is to keep the existing Hub (perhaps not the Hub 3) and media-convert the incoming fibre to copper at the house entry point. Their ultimate aim is to turn DOCSIS off and supply the XGS-PON service instead, which will save them millions in all sorts of costs. The might even plan that to be parallel with the fibre rollout; I'm not privy to that level of information. It's an old migration challenge: progressive vs parallel.
