I agree, they should build layers to side characters. Like we only know about Virat, Sai and bit about Ashwini.
Baki logon ka just basic info pata hain and most of them are single dimension characters who can be defined with just one adjective.
Like you said, though we feel sad for Shivani as she is super nice person, it is kind of difficult to relate to that character when there is no proper build up.
Didn't she get the bf during Samrat's wedding, they would have built it from there, chote mote scenes hi sahi, take 2-3 mins of the time to develop each side character per day.
Also why should drama always happen with the leads. So in a way I am happy that this time the drama was not due to Sai, instead she helps in solving it.
We know nothing about Mohit even though he lives in same house. He hardly gets dialogues since Virat's wedding. No background for Omi and Sonali. How did Mohit and Karishma meet and marry? etc
Given that they air 6 days a week, not every episode needs a shouting OTT scene. Some of the filler episodes can be around side characters.
I can bet CM niwasis will somehow find a way to blame her anyway. They will say if Sai knew amey is married why didn't she stop shivani. Or sai is the one brainwashing shivani etc etc. And eventually when Sai solves the issue, they will obviously say nothing nor will they look guilty/ashamed.
I sincerely want the makers to prove my prediction wrong but i dont have high hopes!