I think https://drafts.csswg.org/css-lists-3/#marker-properties should allow all properties from https://drafts.csswg.org/css-text-decor-4/.

Non-inherited properties

Currently, these properties have no effect on ::marker. I think they should apply.

• text-decoration-line
• text-decoration-style
• text-decoration-color
• text-decoration-thickness
• text-decoration-trim
• text-decoration-skip-self

Properties that only apply to text

These properties can already be set on ::marker so that they inherit into the text inside, where they have effect. No need to change anything.

• text-emphasis-style
• text-emphasis-color
• text-emphasis-position
• text-emphasis-skip
• text-shadow

Other inherited properties

These properties apply to all elements and are inherited, so they also apply to text as per #5303 (comment)

So like in the previous case, they can affect the text contents of the ::marker. However, I think they should apply to the marker box itself:

• text-underline-position
• text-underline-offset
• text-decoration-skip-box
• text-decoration-skip-spaces
• text-decoration-skip-ink