The problem with FD based cards is the limit. Theoretically you can have 100% of the limit but practically for cibil score building you have to hold back and spend 25-30% at max.
So with 20000 FD you will get an usable 5000-6000 limit. To increase the limit you need to increase the FD amount.
If jupiter could offer increasing limits like 150%-200% based on repayment history, credit score, risk profiles ,etc then it could be a very good deal.
Before bill generation, we could use almost 90% of the given limit. I do the same I utilize the limit but pay the amount before bill generation and reduce it to below 30% (credit utilisation below 30% is necessary to maintain) to be billed. But the only problem with this is that we cannot do Emi conversions with these cards and we cannot enjoy full interest free grace period.