We use Citrix at work as well. It doesn't affect my department but I have some experience with it. Unfortunately, I can't confirm if it works on ARM. I know Raiser's Edge recently switched over to Azure, so maybe there's a chance it functions without jumping through hoops, but it's hard to say without actually using it. Additionally, I can post the announcement email for when they upgraded us to Azure:
"As part of this enhancement, we’re leveraging our preferred cloud service provider Microsoft Azure to ensure your solution benefits from industry-leading infrastructure now, and into the future. Blackbaud Raiser’s Edge NXT is taking advantage of Microsoft’s state-of-the-art security and infrastructure. In addition, with this relocation, you’ll use a single sign on to get all users to the Blackbaud Raiser’s Edge NXT WebView through a single URL (no more dual login to Citrix!)."