Yes. You can create a new Slot instance in your Game Instance and use “Save Object”, “Save Component”, “Save Actor”, and “Save Actor Hierarchy” nodes.
All those nodes mentioned above only write data to the Slot object instance, but they do not write to files, until you call manually “Write To File” node.
“Save Game Mode”, “Save Game Instance”, and “Save Game World” automatically calls the “Write To File” function.
I particularly never use those that automatically write save files, I use Slot objects as runtime storage for a lot of things…