The Covenant Build

I also find it strange to go with 0 point in specialist but if silveroak is so sure that created grog don't cost BP then why not.
(Personal I stay with the toolmaker as familiar so this is even covered without a free grog)
Paying for a +2 size as standard lab is great for my magus as it open up 40 points of the BP I expected to be spend
The income of 2 years as vis savings sound fine and enough for me.
So over all I'm ok with it.

Just a reminder we still need to settle how incomprehensible holy magic is toward normal hermetic magic before we really start to pick books and lab text:
https://forum.atlas-games.com/t/incomprehensible-of-holy-magic/11642/1