Is your feature request related to a problem? Please describe.
Not a problem in packs that add silver but not many magic mods add silver and magic packs have been on the rise.
The current oregen is 3 veins in blobs of up to 7 in a Y range of -64 +200
3 veins in a 16*16 space 264 blocks tall is rather sparce to say the least.

Describe the solution you'd like
Comparing the current oregen to that of 'simplified' vanilla (developed in a void), I think I would do 2 passes for the oregen one a more sparce start to finding silver and the ore veins are more common larger as you go deeper.
iron 40, 0-13, 128-320 (192)
iron 6, 0-3, -24+54 (78)
silver 7, 0-10, -48+32
silver 3, 0-3, +32+54
gold 4, 0-9, -64+32 (96 ~> air exposure reduces spawn)

If not that then to do simple and efficiently while increasing spawn quite a bit and giving the player a specific depth to look besides "underground."
silver 8, 0-10, -48+48

Additional context
Add any other context or screenshots about the feature request here.