Can I send the micropayment from a jaxx wallet to prove my btc balance?
JAXX used HD Wallets as far as I know, so no. Use Electrum and sign and message might be the easiest way.
There is nothing wrong with HD as long as the private keys are controlled by you (the user).
Except you can't sign a message with JAXX and when you send the micro tx, it'll change your address rendering the link useless. Use Electrum to sign, easiest method unless you can still sign messages in mycelium.