VisualEditor's "Clear styling" button can not be used to change headings to normal text currently. When editing an article in VE, the heading menu is used for that purpose.

You can use VE shortcuts even if they don't appear in the toolbar. For a list of shortcuts, press Ctrl-? in the Flow VE editor. So you can use Ctrl-0 for this (I realize this is not discoverable for a new user).

In T119600#1838920, @Mattflaschen wrote:

VisualEditor's "Clear styling" button can not be used to change headings to normal text currently.

James F said this is by design (styling vs. block-level formatting), and they do not intend to change this.

In T119600#1838919, @Mattflaschen-WMF wrote:

VisualEditor's "Clear styling" button can not be used to change headings to normal text currently. When editing an article in VE, the heading menu is used for that purpose.

I think we could consider on a given context to remove the formatting that cannot be altered with the tools provided in such context (directly, with a "clear format" tool or a contextual action after pasting). I don't think that what is useful for Flow needs to be propagated to VE.

Article and conversation editing can have their tools adapted to the specifics of the context. In the same way that Flow provides a mention tool (unavailable when editing articles), it could provide a customised "clear format" tool or similar that removes the format that is not common in a conversation context (for which tools are not provided).

I think users who want to clear styling because they have added a header would be advanced users. Can't e provide them an advanced toolbar with all VE options instead?

In T119600#2972223, @Trizek-WMF wrote:

I think users who want to clear styling because they have added a header would be advanced users.

Not necessarily. Quim says this happens if you just copy and paste it, which a new user could certainly do.

In T119600#2972781, @Mattflaschen-WMF wrote:

In T119600#2972223, @Trizek-WMF wrote:

I think users who want to clear styling because they have added a header would be advanced users.

Not necessarily. Quim says this happens if you just copy and paste it, which a new user could certainly do.

Right.
A switch to a more complete toolbar would help then: T93243#2968169

In T119600#2972784, @Trizek-WMF wrote:

In T119600#2972781, @Mattflaschen-WMF wrote:

In T119600#2972223, @Trizek-WMF wrote:

I think users who want to clear styling because they have added a header would be advanced users.

Not necessarily. Quim says this happens if you just copy and paste it, which a new user could certainly do.

Right.
A switch to a more complete toolbar would help then: T93243#2968169

Providing a bunch of options that are not needed most of the time comes also at a price, since it makes it hard to find those you often use.
I think we can have a "more" menu with additional options, but in this context I think it makes sense to keep the top-level tools minimal.

In T119600#2972784, @Trizek-WMF wrote:

In T119600#2972781, @Mattflaschen-WMF wrote:

In T119600#2972223, @Trizek-WMF wrote:

I think users who want to clear styling because they have added a header would be advanced users.

Not necessarily. Quim says this happens if you just copy and paste it, which a new user could certainly do.

Right.
A switch to a more complete toolbar would help then: T93243#2968169

@Pginer-WMF also suggested one possibility is removing header formatting as "a contextual action after pasting". I'm not sure if he means to prompt, or just do it automatically. Both could be worth considering, but I would lean towards the second one.

In T119600#2972788, @Pginer-WMF wrote:

I think we can have a "more" menu with additional options, but in this context I think it makes sense to keep the top-level tools minimal.

I agree. But have a way to have more options is expected: 3 users requested it in the survey's free forms (not the biggest expectation, plus one approved that choice of top-level tools), and that's also something I've heard a lot about (but I can't quantify)

In T119600#2972223, @Trizek-WMF wrote:

I think users who want to clear styling because they have added a header would be advanced users. Can't e provide them an advanced toolbar with all VE options instead?

This is not my use case. I only run into this problem when copying titles of other wiki pages, which I expect to be a relatively common action in wiki discussions. That's basically it, I'm not really missing other buttons to the point of changing from visual to source (although I will pay more attention from now on, just in case my memory is biased here).