Look into hot water circulating pumps.
They may be retrofit into existing home plumbing, are designed to address this exact use case, can be automated (old school timer or more intelligent with a smart switch), and will be significantly better for the environment/ your water bill. Essentially, there's a pump located in your hot water tank closet and a small valve installed under your bathroom sink tap. They cost about $100 (though they say that's recouped quickly because you're not letting cold water run as long anymore), though you'll likely need a plumber — it's straight forward and common.
Now attached to a smart plug you could trigger it to turn on 10 minutes before your morning alarm, not run when you're on vacation, run when your location leaves the gym (assuming you shower at home), etc.
I'm using the Lumary recessed lights with smart switches in always on/smart bulb mode. Home Assistant listens for button press events from those switches and sends the appropriate command to the bulbs. Use Local Tuya so there's no reliance on the cloud. Also look into adaptive lighting so you get the right light based on time of day. Awesome.
Some notes. White brightness is great, but color brightness is poor. Not horrible for ambient color effects, but poor for dedicated color lightning. Also, they sometimes drop WiFi and I need to cut the power (using the smart switch) and restore.
Lastly, if I had to do it all over again, I'd go with Philips Hue recessed Zigbee lights instead. 2x or more in price, but from what I hear they are near flawless. You can also pair them to a Zigbee light switch meaning they still function if the hub were to go down.