No one is going to accept that. After Munich, Hitler had as much credibility as Young Earth Creationism. Him DOW'ing Japan, then trying to leverage it to cut some kind of cease-fire/de facto surrender in the west in exchange for token support against his erstwhile ally would get Ribbentrop laughed out of Downing Street.
Why to any of this?
The loss of Singapore, Burma, and the threat to the Raj was of huge concern to the UK, especially if Japan was able to successfully stoke the flames of Indian nationalism.
And Germany offering Intel in relation to IJN and IJA military codes as Japan planned these operations, could be HUGE in terms of preparing adequate defensive strategies for British troops stationed in south east Asia.
Think about all the operations that the IJA used the element of surprise to their advantage to win.
Now imagine those operations with full defensive preparations.
Intel is a HUGE bargining chip.
And it is NOT asb for Germany to continue offering peace agreements to the UK to help preserve the British Empire as the actually did in OTL.
I must highlight again that Hitler was a pragmatist and could absolutely used war against Japan as a trump card to at least stave off war with the US and possibly a temporary ceasefire with the UK.
Would this have ended LL to the USSR, probably not. But would lack of a second front, coupled with a stoppage of British bombing help the war effort in the USSR, absolutely.