Short Throw shifter plate question

[wo6873]

I have recently installed an cheap short throw shifter on my 2006 WRX and it was knocking on the metal plate (image attached).
I know people usually cut out the affected section out but as I am still undecided about the short throw I have removed the plate completely for now (so I can revert the car back to stock).

Is this metal plate essential/ can it be left out?
What is the purpose of the plate?
Are there any detrimental effects if I leave it out?

Any advice would be appreciated!