Ali Sardar Jafri in his book on Ghalib (published in the Urdu and Hindi script says this:
Translation by me.
"Pronunciation is also important. Many words from foreign languages have become distorted in Urdu. So they have become Urdu words now. That is why I give preference to the spoken forms over Arabic or Persian versions. And I have written Savaal, Girfataar, Nashtar for Suvaal, Giriftaar, Nishtar, respectively. For the words that have two pronunciations I have preferred the spoken one. I have done this based on my personal knowledge. That is why I have preferred Ijz for Ajz and Sataaish for Sitaaish. However, I have been careful to give the other pronunciation within brackets for such words in the Hindi version. I have not changed some words like Khazaan, Charaagh and Nashaat, but I feel that in Urdu they are commonly Khizaan, Chiraagh and Nishaat, resectively, therefore one should write them like that only. Of course it is another question what Ghalib himself said when he spoke. As long as proper research on that is not done we have to use this kind of criteria."
Now You Know!