I have to fly on a route that is operated only by SpiceJet and am faced with a 15KG baggage allowance. However, I am flying in from half way across the world and will also be attending a wedding in India. So it is difficult to restrict baggage to 15KG only. Two questions:

Does SpiceJet have any booking channels (perhaps overseas) that allow a higher baggage allowance?
&
How fussy are SpiceJet check-in agents about the 15K free baggage allowance?