Nowadays you want a MIPS helmet. I don’t see that that Lumos is, although they do sell MIPS models. Personally I’d rather have my Garmin Varia radar rather than lights on my helmet. I use a Giro MTB helmet for both road and mountain; MIPS but nothing else fancy.
I use my Apple Watch 5 primarily for two things in addition to time. The first is glanceable weather. I run the CARROT complication and a wind speed complication, so I can immediately find out what the weather is like now and for the next few hours. The other thing I use a great deal is the Overcast app to control podcast playback on my iPhone (skipping commercials, primarily, but also pause/play). This and anything else requiring using the touch screen becomes more difficult now that winter is coming, with the watch buried under clothing and having to wear gloves. Other uses include Apple Pay, answering calls when my iPhone is hard to get to, occasionally answering texts by dictation. But mostly it’s time, weather, Overcast. I don’t use it for anything fitness related. (You can’t stop it from counting “steps” or heart rate, but you can keep it from nagging you about it.)