About Descriptor Buffer

Hello, when I use VK_EXT_descriptor_buffer

May I create arbitrary large size of buffers using APIs like vkCreateBuffer, vkAllocateMemory
as long as GPU and system have such memories (of course, larger than minimum required) ?

and with those created large buffers, may I set the pointer (ptr below) to any arbitrary position
when I call vkGetDescriptorEXT(device, &descriptorinfo, descriptorsize, ptr)
as long as no memory violation or overlap occurs ?

If so, I can just create one large buffer and call each vkGetDescriptorEXT with moderate ptr inside, as long as no memory overlap occurs, with nonsystematic manner in any orders without caring types of descriptors (uniform or image or sampler etc) if memory property flags and usage flags etc are OK
Is this correct ?