HB in specified accomm and also UC - SDP issue

If you are trying to get someone who has HB because in specified accomm and also UC back onto legacies because they’ve subsequently been awarded PIP … are your HB departments willing to give a confirmation that there is an SDP in the calculation of HB, or are they saying that UC passports to HB so there is no SDP in the calculation.

This by CPAG says HB still has to be calculated:
https://cpag.org.uk/welfare-rights/resources/article/sdp-gateway#footnote6_1533mfh

But we wondered if this is being achieved in practice?

In my experience this hasn’t been an issue - DWP has accepted that PIP+HB = SDP. When I discussed it with the LA they said DWP wouldn’t even bother checking (this particular case was an ESA claimant moving to a different LA).

However, I’m not sure how DWP will respond to trying to withdraw a UC claim - people seem to encounter issues here (although I’ve also had clients who have ‘accidentally’ withdrawn their claims…)