Visit visa application - 2 year option

Good day,

I'm sponsoring my brother to visit me in the UK in September this year. He is a national of a third world country and is currently a student in Germany. He has previously been to the UK 3 times (the last time was in May this year for 15 days) and each time he has returned on time.

The previous visas were based on applications for 6 month visas so this time I'm encouraging him to apply for a 2 year visit visa. I usually take care of all of his expenses as he is a student but he also shows his bank statement with his savings.

The problem this time around is that his German visa is expiring on 20 Sept 2021. After this he will get the visa for another year from Germany as he will go to the next year of his degree. Its usually a quick and easy process at the local council office to update the visa over there. However, I'm worried that the UK visit visa may get rejected if his current visa expiry date is so soon.

We have checked if he can renew his German visa earlier but the earliest appointment available is 06 Sept.

His planned UK visit dates are 25 Aug to 10 Sept. He has an enrollment letter from his university which states that his current term ends on 20 Sept and they have said they don't give any customised letters for visa processes. In the past he has used the same type of letter for UK visa process without any issues.

In these circumstances, do we have a risk of his visa application rejected? We will be losing a hefty amount and he will get a rejection on record which we are trying to avoid.

Your guidance would be highly appreciated.

Thank you.

A gentle nudge. Any advice would be appreciated.

If its the wrong forum, kindly suggest which forum should I post to.