Unmarried partner visa advice - cohabitation

[AliciaYYY]

Hi everyone,

For the context, my partner is applying for an unmarried partner visa (I'm the sponsor) in the UK.

There is this form about “Consent for the Home Office to verify third party information", stating that if anyone's name is on a joint document provided by my partner, that person should sign this form to give their consent to check their information.
My partner was renting a room in a flat share for 6 months, and to prove that, she will upload her tenancy agreement. But her flatmate at the time was harassing her, so there is no chance we would ask him to sign anything.

My question is: should we not fill in this form, and explain somewhere else (in a cover letter for example) that it is not possible to include that person due to harassment? It sounds a bit weak in terms of "it's my word against his". I'm looking for alternatives, or if not filling in this form for that specific tenancy would be something acceptable.

I'd appreciate any advice！Thanks!

[CR001]

How is the 6 month flat share relevant to the mandatory documents required to apply for an unmarried partner visa where you have to prove you lived together for 2 years?