The examples are best in case the questioned constituent contains a wh-word and nothing else. So the following sounds quite well:

The example above sounds much worse if the constituent wat foar boekenwhat kind of books as a whole gets doubled:

A possessor phrase does not sound right either, if it is doubled:

It seems that doubling the phrase as a whole improves if the complementiser asif is added:

Adposition Phrases (PPs) seem grammatical as well, as is illustrated below:

It remains to be seen whether examples such as the above can be attested or whether a systematic survey bears out the judgments reported here; not everybody shares the judgments reported above.

Embedded clauses in the form of a V2 clause can enter the single question phrase construction:

Perhaps the last example in (7) involves a mere repetition, but then we are in need of criteria distinguishing syntactically licensed repetitions from mere repetition.

The resumptive topicalisations in (8) do not sound bad either:

It is possible to have V2 in the embedded clause, as in the following example, with the topic pronun at the beginning of the embedded clause:

By and large resumptive question formation is on a par with resumptive topicalisation. Both are allowed in Verb-Final and Verb-Second constructions. Resumptive topicalisation is not allowed with an embedded V1 clause: