LCD display screen.
There is only rectangular window with chamfered edges stamped to the front panel in front of the display on original machine. To prevent coffee or water splash to get inside to the electronics, I decided to make some cover on it. Display screen is cut from 3mm acrylic glass on laser engraving machine. The machine was only the basic one, no accurate enough, so I have to trim the glass on sand paper to snug fit into the stamped window. It holds by friction only, which is pretty good - it is not possible to remove the screen from the window unless you use some 3M double sided adhesive tape. Now it's much easier to wipe out front panel with the towel in case of coffee or water splash and no risk of water to get inside.
(unfortunately I have no picture of original front panel before upgrade)
Steam wand insulation.
Steaming is very powerful on Studio, but also steam wand silicone sleeve gets hot quite quickly. I decided to put Teflon hose inside the wand to make some extra insulation. This helps a bit, but not entirely (for longer steaming, which is usually not the case).
Shower screen hexagonal screw.
Instead of "ugly" hexagonal screw I used countersunk stainless steel one with allen head (slightly trimmed in diameter with file and Dremmel while spinning in the drill machine). This is straightforward upgrade, it's enough to tighten the screw and the shower screen, and the screw head makes the seat itself - the diffusor has already recess made from the factory. I suggest to remove the diffusor from the grouphead and do the shower screen "shaping" with the screw and M6 nut rather than risk the thread damage in the grouphead if the screw is overtighten.
(original hexagonal head screw)
(new countersunk head screw)
I also tested IMS precision shower screen,
but surprisingly the original DC one seems to distribute water better, IMHO.
DC original shower screen coffee pucks
IMS precision shower screen coffee pucks
Shock absorbers replacement.
As mentioned in intro thread, DC has made running change in the production and uses softer shock absorbers for pump motor to reduce the vibrations. Why not to do the same? I used soft 45 SHa D15x10mm M4 shock absorbers and replaced original ones. Together with replaced pump (for the new type, replacement under warranty because of pressure gauge hand shaking) noise level has been significantly reduced and drip tray grid unpleasant resonances have gone.
Olive-ization.
Pictures are self-explanatory enough ...

(olive wood + OSMO hard wax oil matt)