Zephyr device tree: how to get the values of the named properties of a phandle behind a phandles, for all compatible nodes?

Question

In my Zephyr DTS binding I have a node with a given compatibility, let's call it my_compatibilty, with an optional property of type phandles, let's call it things, allowed to have up to two elements. In my driver code I can build up an array of the leaves of this tree; for instance, I can make an array of the values of a string entry flibble within things, or NULL if not present, for all compatible nodes with:

#define GET_THINGS_LIST(i, name) {DT_PROP_BY_PHANDLE_IDX_OR(i, things, 0, name, NULL),  \
                                  DT_PROP_BY_PHANDLE_IDX_OR(i, things, 1, name, NULL)},

static const char *const leafValueFlibble[][2] = {
    DT_FOREACH_STATUS_OKAY_VARGS(my_compatibilty, GET_THINGS_LIST, flibble)
};

This is now easy to manage, a nice ordered list I can work with from C.

HOWEVER, I now need flibble to be a phandle-type property. How do I extend the macrobatics above so that I can still get at the leaves of the tree, i.e. for all compatible nodes, create arrays of the values of the named properties within flibble (or NULL/-1/some-known-value if not present to keep the order)?