There was already barely enough room in the three pages we got for pathways and impact summary. I can't see it will be possible to squeeze anywhere near 3 pages for impact out of the case for support without compromising the research
Not clear whether and how impact will be reviewed - at present panels can request a poor pathway to be revised as a condition of funding
I can see an entirely rational response for non-applied proposals to give a short paragraph to impact at most. Even if panels can still ask for revisions to impact, you get a competitive advantage if you devote 99% of the case for support to research and revise if funded
You never have enough space to do the research justice in the case for support, so I can't see even the most hardened opponent of impact welcoming an additional pressure on that already precious space
You want to simplify the paperwork? Why not target the academic beneficiaries and objectives sections, which almost always overlap with content from the case for support
Hack: give yourself an extra page for impact in your case for support by creating headings for "objectives" and "novelty, timeliness and academic significance" (headings I commonly use and see), and under each, cross-reference to objectives and academic beneficiaries sections
