I use nginx proxy manager and then a cloudflare to protect my actual IP

IMHO color temperature, dimming or color are the best thing of smart bulbs

I got a second hand HP Elitedesk mini from ebay. they are small and quite affordable.

I run way to many stuff on it.

it’s not that it cannot be done. the issue is that something as simple as acceding a service should not require to configure wire guard and routing rules. plenty of FOSS projects are safe to expose through a simple reverse proxy

and then you are giving access to your lan to people whose computer you don’t control and might be full of malware.