For a fully accelerated CI/ECI rider on a life plan, would this be considered CI coverage only? Do I then have to get a separate term plan to cover death/TPD/TI?

Yes. Your full sum assured of 300k will be accelerated (maybe subjected to cap for ECI depending on your policy terms). Once 300k paid out for CI/ECI, your policy will cease.

You may consider term plan to cover for your life when necessary.

Hi Anon, spot on, the WL plan you have I would consider is only for CI and not for the purpose of death cover. So I would top up a 600k Term Policy covering Death.

However do consider a 1M policy as they usually have quite a big discount and most policies allow you to buy 50% more upon certain life stage events without a health declaration and it wouldn't be that much more expensive.