My piece of advice
Rather than Crappy 10w30/10w40 oils, next time shift to 5w20, along with genuine filters,
Reason, 20 is ideal viscosity for k10b, meanwhile 5w oils have lower noack loss figures as compared to 0w oils, so 5w20 is ideal in your scenario
And observe consumption too for 1-2 oil changes
As for now, with 5w30, as you mentioned oil was at 75%, in k10b dipstick, upper point is at 2.9 and lower is at 2.5L
Means your car is burning approx 100-200 ml in 5k kms, which is really good and not an issue considering you have already done 80k+, engine health is 9/10 I would say, suzuki mentions that 1L in 1000 kms is max normal consumption, and in your case it's a lot lower, so nothing to worry about
And please don't pay heed to bunch of crooks on dealerships, they will misguide you everytime