Only log what you shared
Flights and trains are usually booked by each person for themselves, so leave them out. The split is for money one person paid on behalf of others: the villa, the scooters, the meals, the airport cab.
Split the drinks tab properly
The shack bill is where equal splits go wrong. Log it as two expenses: food across everyone, drinks across the people who ordered them. Unticking names takes a second, and the people on lime soda stop paying for the cocktails.
Scooters and fuel
Scooter rent in North Goa usually runs ₹400 to ₹700 a day, more around Christmas and New Year, and fuel is extra. If two people share a scooter, split its rent between them. If everyone swaps around, split it across the group.
Someone joining for two nights of four? Use shares, one per night, and the villa splits by the nights each person stayed.
Signal drops, entries do not
Mobile data comes and goes at beach shacks and on the ride back. Entries save on the phone and sync once you are in range, so nobody has to remember to add it later.