I don't think consummation will happen immediately.
Characters
V is delirious at Sai calling him Virat. And although Sai had waited for BK to know the truth, it came out in a very sudden and sad manner. V got slapped. Sai is distressed. So even though they are logically ready they are not in happy and relaxed mental space right now.
Atmost i feel (going by the BTS chat) is pillow wall demolition and some cuddling hugging ... Implied first base 😉
For story and drama quotient
Them having not consummated will be higher drama.
Sai getting kidnapped and being with Jagtap will make V highly vulnerable emotionally.
Sai on the other hand might relive those memories and her trauma will be back.
Pakhi however, while she has given up on V, will continue holding grudge against Sai and in her frustration might seed the doubt of Sai's chastity in everyone's minds.
And if fake pregnancy is skipped, V needs a jolt to finally break from Pakhi and whatever leeway he has been giving her.
This accusation by her will see V supporting Sai no matter what and while it will indeed make him mahaan it will also serve a greater message that his love or true love is not physical. It could be however the final straw for his continued attachment for Pakhi when he realises her true colours.
And since BK is already against Sai, she would ignore this jibe from Pakhi like the drugs wala jibe.
I mentioned YHM in another post, where FL faces a similar situation and ML and her MIL stand be her and reassure and help her overcome the guilt of it all.
If Ash does this, that might be her redemption as well.
From technical point of view... Big C can then be extended further.
I do feel however, that Jagtap track is somehow related to the organ stealing/child trafficking track. Dr. Thu might be cruel but he is a good man (cancels fees for a poor patient)....
So if they do want to increase the drama and extend the track for month easily... they can show Sai getting embroiled in the scam, Dr. Thu accusing her. Jagtap enjoying from sides (not revealing that he is back) considering it as a revenge for spurning him... V trying desperately to prove Sai innocent... And in the end, SaiRat come out victorious and Dr. Thu finally has a good impression of Sai and becomes her true mentor and supporter.