but if you start to count degrees about graves facing Petra
Ok, the word Petra triggered you. I should have avoided it. Fact is that these graves are 90 dg away from Jerusalem, perpendicular 30 dg away from Mecca, just as the ancient Qibla.
The focus doesnt need to be Petra, but the direction is (probably) coincidental towards Petra.
It's a fact that the direction is NOT Mecca or Jerusalem.
Qastal is again located where it is impossible to miss Mecca in this way. Instead of pointing S-E, the qibla points S-W.
I think you are right . If Petra was the focus, we would have known. But on the other hand, you seem to be a believer. You are trying to fit the narrative to a location as if it did happen.
Why can't the scenario be: No Mo, no zamam, no Kaba. The whole story is the product of the imagination of 8-9 C storytellers. But in 7th C, for some reason, the Umayyads felt the need to focus their Qibla at 190 dg in Qastal.