Do you think it might be possible to avoid labelling views as "realist"? I hate to say it, but it just sounds like a "pop" philosophy sound-byte.
If one were criticising the "sarvam asti" or svabhava "realism" of the Sarvastivadins as "Realism", I think the limited context would probably be quite appropriate in a specialised discussion.
But, given the many shades and colours of "Realism" in both Western and Eastern world-views, I am not sure if "Realism" should be used so loosely.
For example, we have the Pali Abhidhammic notion of sabhava, but which the Commentators are quick to sanitise into a notion of "that which is being borne by its own conditions"; how much "realism" is left in this?
Or how about the many instances of "atthi" and "natthi" used by the Buddha in the Canon to describe states? We of course accept that when a dhamma "atthi", it is so by virtue of DO (the very same point given by the Commentary to the Dhammasangani above quoted). Likewise when a dhamma "natthi" - that goes by way of DC. Does this make the Buddha a "conventional" realist?
Personally, I don't think the Buddha was interested in the ontological implications of "atthi" and "natthi" for the world out there. The standard translation offered as the 2 philosophical extremes to be abandoned are "Everything exists" and "Everything does not exist" (eg SN 12.15). I think the "everything" should simply be "The All", discussed in SN 35.23 and SN 35.24. Certainly, the All do include the external kāmā out "there", but I don't recall any DO discussions that address the state of the kāmā - DO is invariably applied to our internal world.
Even Ven Nanavira slips into "conventional" realism when he says "though both are objective in the experience".