Accommodation-Joint Bank account

Hi,

A bit of a complex question.I might be overthinking it.

I am currently on the Graduate visa in the Uk and living with my partner.I am planning to apply to the Appendix FM visa in about a year time.Our accommodation is that he bought a flat as a shared-ownership.50% belongs to him and he pays morgage and 50% belongs to house association and he pays rent to that.I have always been an occupier and not on legal documents.I have also been sending money directly to my partner to contribute into the household costs.But this week we have decided to do a joint bank account as it will be perfect evidence for partner visa and will work well for us.Then I started panicking because I don’t know if shared ownership purchase is treated as a social housing like council house aallocation? (because of the rent to house association) and therefore it is considered as a welfare benefit from immigration perspective.Equally immigration lawyer I have contacted consider this scheme still like a proper house/flat purchase or a contractual arrangement .Obviously me as an occupier doesn’t cause the problem of me breaching the visa condition.But because now morgage and house association rent will be going from our joint bank account with my name on it,I don’t know if it will ever cause any suspicion.Not sure if I am just simply overthinking it.He doesn’t receive any type of welfare benefits and we both work full-time so…

Thank you !