TMP451: Question about the package pins - the exposed Cu along the side-wall

I have a customer preparing a mounting process for the TMP451 onto their boards.

They want to coat the package to prevent environmental "materials" (ie grease, fluids, etc) from affecting the device lifetime.

1. The pads have NiPdAu plating on the bottom (side that connects with the PCB), but as the lead-frame is sawed after coating, the metal of the pins exposed at the side-walls of the package is just pure Cu, yes? There is no coating, yes?

2. If so, then would coating the device to prevent contamination/oxidation have any affect on the device performance? Most notably the local temperature sensing performance. (I don't believe so...for 1 because the PNP transisfor for local temp sensing is integrated into the device Silicon, and doesn't have an exposed pin - yes?)

3. No problems with the remote sensor or other pins...?

It is safe to assume the coating material is an insulator, and non-corrosive.

EDIT: They also mentioned the TMP451 device package has protruding(visible) metal along the outer-sides of the package...is this normal?
For clarification, there are four sides to the package. Two sides of the package have visible copper due to the 8-pins and the nature of the package. The question isn't about this. Aparently there is visible metal on the two sides that do not have "pins".

This confuses me...I know the TMP461 package has some extra pins, so each side of the package will have some visible metal. But the DS for the TMP451 doesn't show metal at these points...

Any enlightenment as to what this metal could be would be helpful (also, if known, is this bare Cu? I would assume so, as the plating is done before the sawing process, so the metal on the walls would be bare Cu)

Thanks,

Darren