Discretionary leave to remain Extension

Hi everyone and experts

Asking this question on behalf of one of my friend

My friend currently got ILR and all kids are British. when He applied for ILR, he also applied for spouse visa for his wife (he can't remember which form he used) but because of English requirements, HO rejected and gave 3 year DLR where she becomes eligible for ILR after 6 years.

By last year, their financial circumstances change massively. First they get evicted by house Under S 21 of housing act and then put in Temporary accommodation which is self contained 2 bed flat provided by council. Last year He was unemployed and went on Income based job seekers allowance.

Currently he is working nominal hours, living in temporary accommodation,claiming Child tax credit, working tax credit, housing benefit and council tax credit (making a contribution of about £200 per month for flat).

Now he wants to know

1) which form to use for extension?

2) As house eviction was carried out under S 21 of housing act and case was decided in county court by judges finally involving bailiffs. Judges decision got wife's name on court order, are they suppose to reveal it in form and how this may impact their request for extension?

3) Does claiming benefits and living in temporary council accommodation can have detrimental impact?

4) What supporting evidence they have to provide and what fact they have to support?

5) in reference to Q no 2 specifically and other circumstances in general above how this may impact husband's application for British citizenship , is it compulsory to reveal that while applying for certificate of Registration? since then he has completed 14 years now in the Uk and more then 2 years after getting ILR.

thanks in advance for everyone responding here.

hi everyone, is this too complicated scenario?

do you think they should consult legal expert?