I sometimes get warning of putting

modifier

as first optional argument. May I know why? I've some Custom Composables like

HeaderText

which used to have first parameter the text itself so I didn't need to write parameter names explicitly, but putting modifier as first parameter makes me lose this power.

First optional as in, you can still have the (required) text of a

HeaderText

come first. The intent of the guideline is that you can always supply a modifier to a compose UI function without using named parameters, it always comes right after the last required parameter.

Okay, so if my Composable has all optional parameters, modifier should be first among them?

Yes