Why is captive-core not working in mainnet or pubnet in stellar-quickstart?

[sj602]

What version are you using?

stellar-core: 19.11.0
horizon: 2.25.0

What did you do?

I wanted to run stellar-quickstart docker image for testnet in captive-core mode, using this command
sudo docker run --rm -it -p 8000:8000 -v /home1/irteamsu/stellar:/opt/stellar -e PGPASS=stellar -e PGPASS_CONFIRMATION=stellar --name stellar stellar/quickstart --testnet --enable-horizon-captive-core
But I found that the start script in the image is coded that it only works for standalone or futurenet in captive-core mode(refer to: https://github.com/stellar/quickstart/blob/master/start#L36)
Why is that? is that a bug or a right instruction?

What did you expect to see?

What did you see instead?

[github-actions]

This issue is stale because it has been open for 30 days with no activity. It will be closed in 30 days unless the stale label is removed.

[leighmcculloch]

According to git the captive-core functionality for standalone was added by @2opremio:

• Add support for captive core (standalone) and manual close #212

@2opremio do you remember why we limited captive-core to standalone?

[leighmcculloch]

Reading between the lines this comment in Slack might suggest we added it for standalone only because that's all we needed it on at the time because we were adding it to support using quickstart in integration tests with captive-core in use. Thread is here:

• https://stellarfoundation.slack.com/archives/C02B04RMK/p1603144846314800?thread_ts=1603144568.314000&cid=C02B04RMK

[sj602]

OK. I see.
But I want to use captive-core in stellar-quickstart. Do you guys have any plans for deleting the limitation?