@blue_ingle
I have a different opinion about your statement above .
Assuming you are only endorsed with a multi commercial on your foreign license and you pass the single engine skill checks in India . I dont see any reason why the DGCA should not endorse the single engine aircraft on your DGCA license .
The skill checks are the equivalent of the FAA checkrides .
If you pass the single engine Indian checkride ( i.e skill checks ) then you should have it endorsed on your Indian license irrespective of whether you have it endorsed on the foreign license or not .
This is same reason why the DGCA asks for the IR check to be done in India when you dont have an IR endorsed on your foreign license .
What I am trying to say is even if you only have a multi commercial on your foreign license .
Do the Single Engine skill checks in India and get that endorsed on your DGCA license .
Go back abroad and finish of the multi and other recency requirements ( like 5 hours instrument etc )