Yes, these are interchangeable phrases. You could also ask: 1. Are you following along? 2. Does any of this make sense?

Yes, you can use these phrases interchangeably in many contexts because they all express a similar idea: asking if someone comprehended or grasped something that was said or explained. However, there may be slight nuances in meaning and usage: "Did you understand any of that?" - This is a straightforward question asking if the person comprehended any part of the information or explanation. "Did you follow any of that?" - This implies not only understanding but also suggests the idea of tracking or following along with the information as it was presented. It can be used when the information or explanation was somewhat complex, and you're asking if they were able to keep up with it. "Did you get any of that?" - This is a more casual way of asking if the person understood or comprehended any part of what was said. It's often used in informal conversations. In most cases, these phrases can be used interchangeably, but the choice may depend on the level of formality and the specific context of the conversation.

Yes, these are all interchangeable. FYI, in 'Did you get any of that?' GET could also mean HEAR as well as UNDERSTAND.

Nothing is ever truly interchangeable. I’m standing next to you and we’re listening to someone speak. I don’t know you or your level of English, but I know you’re not a native speaker. I’d only say ‘understand’. ‘Follow’ speaks to things other than English and ‘get’ would be reserved for native speakers. Same but it’s a complicated engineering problem with multiple steps. I know you speak English. I’d say ‘follow’. I already know you understand something, my question refers to following the argument. There’s an announcement at the airport but I can’t hear what was said. My son next to me is a native speaker with better hearing than me. I’d use ‘get’. ‘Follow’ would be wrong because airport announcements are simple. ‘understand’ would be ok but longer and less efficient.

Agreed with comments below. I would use "did you get any of that?" in a more informal environment (asking a friend in class, for example) and the other two in a more formal setting (asking someone you might not know well or not know at all). But I feel it's a more personal choice.