Future challenges for DMT comprise a list of areas and topics that need to be addressed from the same framework and principles as the ones that have been formulated so far. They involve a number of obvious issues.
Present challenges can be inferred from what people have said so far about DMT in published work. The most recent version of DMT was published in Slowing Metaphor Down: Elaborating Deliberate Metaphor Theory (Gerard Steen, Amsterdam, John Benjamins, 2023). This book was reviewed in several places, and links to the reviews can be found here (4D model). Most of these are based on chapter-by-chapter summaries, which provide quick orientation to the major ideas.
Past challenges concern previous criticism of the original model of DMT, which was published from 2011 on, mostly in journal articles. Links to these critical engagements can be found here (3D model), occasionally with further responses. Most if not all of this older criticism has been addressed in Slowing Metaphor Down.