On my 410, I have Nick's tappered pistons, 4 hole x 1.4mm 600cst oil front, 5 hole 1.4mm 500cst oil rear, kit springs all round.
I did try gluing holes with the same glue I use for my tyres, but I wasn't convinced about how they felt, copied one of Adam Skelding's set-ups for the tappered pistons, not looked back
Can't say anything for the 210, not got one.