Good starting point, the weak point in the design is the 90degree transition from the horizontal extrusion to the vertical. You will need large braces to prevent this joint flexing. Imagine that joint evening the fulcrum and the distance to the spindle nose being the leaver. I found out the hard way!!
Keeping thing quiet with a custom C Beam XL
Build in 'X/Y Table Style CNC Mill' published by Mirthgiver, Jan 16, 2021.
A small form factor machine in a soundproof enclosure