See https://1drv.ms/b/s!Aqj-Bj9PNivcn-MfckCWPYEAplaCJw?e=5TZtui for a copy with my comments
and editorial nits inline.

Summary:
1. I am confused by the discussion of "forwarding" packets addressed to the Active Router's address.  The Abstract and Introduction seem to talk about doing it but then section 8.3.1 says not to.
2. Missing discussion of DHCPv4.  Section 1.3 seems to imply that static configuration of end hosts is the primary mechanism for learning default routes, which is not the case for clients or IoT devices as far as I know... DHCP is the default.  I believe VRRP can still be used in a DHCP scenario and the document should say so.
3. Section 4.2's discussion of IPv6 is confusing to me (and I wrote one of the relevant RFCs).  If there are two routers sending RA's on the same LAN, then by default all hosts learn _both_ of them.  The text implies half learned one and half "are using" the other one.  This text needs to be clarified and then probably reference RFC 4191 and RFC 4311 for more discussion.  Even better would be to update the text to specifically discuss the interaction between VRRP and 4311 (which I think would be straightforward), and if needed mention different cases for the different host types in RFC 4191 section 3 (it's also possible that the interaction with VRRP is the same for all the types and the types need not be mentioned except to say that the interaction is the same for all the host types there).
4. A couple places use "should" in cases where it's unclear whether it means SHOULD or MUST (or even "MAY" when "may" occurs earlier in the text).  This could adversely affect interoperability if it meant MUST and someone interprets it as optional.
5. Section 8.3.2 says to log when multiple routers advertise priority = 255, but doesn't say to log when multiple routers advertise the same non-255 priority.  It says not to do that, so why wouldn't you want to suggest logging any time the same priority is advertised by multiple routers?  I.e., why is the logging recommendation limited to the 255 case?
6. Various grammatical nits.