Which is better - choosing With or Without Conversion at ATM in Sudan?
You'll be using cash for almost everything, especially for hostels. While some larger hotels might accept cards, most hostels will not. I stayed at an independent guesthouse that only accepted cash. My advice is to assume your cards won’t work and bring hard currency to exchange. It's much simpler than dealing with a broken card machine or an unreliable banking system.
Forget the with or without conversion question. I was there last year and did not see a single ATM that accepted a foreign card. It's a very cash-based economy. I stayed at a small guesthouse and the owner was very clear that they only accepted cash. You should assume that all your payments will be in cash. It's best to have plenty of cash on hand.
I wouldn't even risk trying to use a card in a bank like Bank of Khartoum. The country's financial system is a very complex and unstable environment for foreign cards. The ATMs simply don't have the capacity or the infrastructure to handle foreign transactions reliably. My advice is to assume your card is not an option and bring cash. The US dollar is the best currency to bring for exchange.
You're going to want to avoid ATMs in Sudan altogether if you're a traveler. Due to sanctions and an unstable financial system, foreign credit and debit cards, including Visa and Mastercard, are not reliably accepted at ATMs. The issue of with or without conversion is moot. The best way to get cash is to bring US dollars or Euros with you and exchange them at a bank or a reputable money exchange office.