Remotely updating parameters on ESP8266

Just learning here and wanted to ask for some options on this topic. Currently I have an ESP8266 based board that I'm using WiFiManager to setup the WiFi settings remotely and this is working great!

I'd like to be able to update / setup other parameters like your standard MQTT things. Yes, I did read the section on how to alter WiFiManager and in that section it states that it is a little complicated to add your own parameters. Before I dig into this, are there other options?

Since I can setup WiFi remotely now, would uploading a JSON file remotely and then triggering a restart be a good way to go?

Is the best way to just deal with the extra code of altering WiFiManager?

Another option stated in WiFiManager was to create another site that could be remotely accessed from your board and via a REST call have the information pulled in that way. I'm not leaning towards that because then I need another service to configure my boards and cannot do it directly. Am I missing something here and maybe should look deeper into this idea?

As far as the programming goes, I'm really happy with the project and impressed I've got it working so far HAHAHAHA! I would just like to lean on the experience in this group to help me focus on where I should go next since I'm new to this field.

Thank you