A few MTU questions

[FormBurden]

Been reading about MTU lately and trying to get my network to be the most optimal it can be. From a lot of research online, I've gotten confused on a few things.

Knowing the standard default is 1500 for Ethernet on MTU, when it comes to VLANs (which I do use), does keeping the defaults on everything work out? From what I can tell, on my PC, all my routers, and OPNsense, everything says 1500 for MTU. On the defaults, like this, what about VLANs? that add 4 bytes to the message. Do I increase the 1500 somewhere (parent interface?), or are their already automated systems in place (usually), that adjust these kind of things? Therefore when I have VLANs going on OPNsense, and going down my other routers within the network (that are also 1500), I don't need to change anything?