How can I stop Electrum re-using change addresses? I had three addresses containing BTC in my main Electrum wallet.

I then performed more than three sends, to addresses not in my wallet.

The first three sends used main wallet addresses to send BTC from, depositing the change each time in the first change address where it gathered.

Sends after that sent BTC from my first change address, but they sent any change back to the same change address, which isn't ideal. How can I stop Electrum sending change to the change address it originated from, in these cases?

Update

According to Electrum documentation, addresses can be frozen. This seems to only affect where BTC are taken from, however; the docs don't say how to affect where change goes.
Electrum waits for confirmations to create new addresses, so if you make new transactions before the previous ones are confirmed, you'll end up reusing the existing change addresses.