Water proofing deck spigots

Hi everyone, i have a deck were going to tile.

The substrate is xcem fibre cement panels.
https://www.xcem.com.au/?gad_source=...0aAntkEALw_wcB

Underneath is just an open area so its not mission critical to have it fully waterproof. Just a nice to have and help protect the steel joists.

But basically im going to apply two coats of undertile water proofing but im just wondering how far up the glass feet spigots i should go?

Ive used the silicon/bondbreaker stuff the crommelins mob recommends to seal the base and the bolt/screw heads. But I just intended to just paint the flat section of the base.

Is that enough? Only doing that far to stop any water wicking down the bolt holes.

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Attachment 537517