Stainless steel plate needs standoffs ?

[DonnyD]

Keyboard will be handwired, so no additional stability from PCB.
My diy plate will be from stainless steel (1.5mm as usually). As it will be 60%, is it necessary to have standoffs ? For example Vortex Core has steel plate and uses 5 standoffs. If standoffs will make a difference, maybe 3 is enough (as in my hand-drawn sketch below) ?
Case will have borders on the sides to hold plate.

[MatchstickMan]

If all the support you need is in the middle of the board, you might be able to get away with just 2; one above D and one above K. For 3, you could go above S, GH, and L.

[DonnyD]

I think i will go with 2, then. Thanks !!
Where should i cut the holes, between switches or rows (photo)? As it will be hand-wired, screw wont go completely trough as with PCB would be. Screw head will touch plate, so hole will be only 2,4mm in diameter (M2 screws will be used).

[MatchstickMan]

Wherever you have the most space, I'd say. I think you normally have more room above/below the switches as opposed to side to side, especially if you've got the slots to remove the tops of the switches.