Which admin command system do you use for your Roblox game?

For your own dev tools Cmdr by evaera is worth a look. It's a proper console with autocomplete and typed arguments, and you can write your own commands in a few lines.

for testing just use HD Admin or Adonis, both cover kick, tp and fly out of the box and you can lock them to your user id. bloat isn't really an issue for a few commands. if you only want admin while developing, write a tiny chat-command script yourself and delete it before launch.