Mortgage qualification w projected SS?

Can a retiree use projected SS income to qualify for a mortgage or do they need to be claiming already to use it?

Scenario: Retiree has hit full retirement age drawing pension which covers current expenses plus ample savings/brokerage they could use to fund mortgage payments plus 401k they havent started tapping into. Their worry is they wont qualify for a mortgage to relocate unless they are drawing SS. They'll likely wait to sell current paid off home after relocating. The retiree claimed SS recently but doesnt need the $ currently and is considering paying it back and waiting until 70 (or as long as they can afford to comfortably). They claimed thinking they might not reach beak even age and could would need SS income for mortgage qualification. But instead of investing it or to relocate, they've left it in checking doing nothing. Waiting to claim would better address their #1 risk, longevity.

I know a mortgage broker can answer this but they'd rather worry about hypotheticals than talk to a professional.