  In the 1st part of this work [DHdS18], we studied affine group schemes over a
discrete valuation ring (DVR) by means of Neron blowups. We also showed how to
apply these findings to throw light on the group schemes coming from Tannakian
categories of D-modules. In the present work, we follow up this theme. We show
that a certain class of affine group schemes of "infinite type", Neron blowups
of formal subgroups, are quite typical. We also explain how these group schemes
appear naturally in Tannakian categories of D-modules. To conclude, we isolate
a Tannakian property of affine group schemes, named prudence, which allows one
to verify if the underlying ring of functions is a free module over the base
ring. This is then successfully applied to obtain a general result on the
structure of differential Galois groups over complete DVRs.
