Moving from full service to live service area as a UC claimant

I previously had a client who withdrew their UC claim very early on in a full service area with any problem but I have concerns about another client hoping to end their UC award.

Client is receiving UC in a full service area, he has health problems so has been submitting med certs for the last couple of months while waiting for WCA. He is homeless and has just been offered accommodation in a different borough which is still a live service area.  I am aware that UC full service claimants take their claim with them affectively so even in a live service area he should be able to just add the housing element to his current claim however….new landlord is refusing to take a UC claimant stating that they have had such problems with UC they only want HB claimants.

Client has enquired about withdrawing UC full service claim so that he can take up this accommodation and to claim income based ESA and HB.  Is there anything preventing him from ending his full service UC claim and claiming income based ESA and Housing Benefit in live service area other than the administrative nightmare that might be?