10 year long term UK visitor visa for Parents

Hi All,

Application from India.

65/68 years old parents - runs a small business and has strong ties to show to home country.

They have travelled to UK once in 2017 and next in 2020 on 6-month visitor visas. They have travel history to US as well (twice) in last 10 years - their 10 year US visit visa is expiring next year. Never had a problem with overstaying etc.

I am a British citizen now, own home, stable job etc.

I understand it's all on officer's discretion - but could this be a case where a 10 year long term visit visa could be granted - its a significant visa cost now these days?

I will be providing reason around frequent visits to keep in touch and now that they have grand kids in UK.

Any advice is welcome, thanks