Hi NordicCNC - I ended up making a hole in the side inlets - 2.5mm I believe (as hiwin spec sheet) and using the small blanking bolts to seal the holes when not in use. Then used a conical adaptor for the grease gun to grease from the new holes - seems to work well.

Got around to upgrading my machine base - ended up getting 12mm aluminum tooling plate and using the router to drill 100 M8 holes @ 75mm spacing. Then the fun of tapping 100 by hand:)
I'm sure a thicker plate would give even more rigidity but It's much more rigid/less deflection than the 12mm ply ! Plus no more threaded inserts falling out all the time. It's also nice and shiny (for now)..
Added a ply spoilboard for now, but planning to use phenolic on top in the future.

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