You can only do what you can do. And I'm fine with the option you provided.It has plenty of memory for firmware updates. It has limited NV memory for user data storage because at the time it was designed the FLASH chips used were the largest capacity available.
The Mark II has larger capacity FLASH chips because they're available now.
Frankly the whining over this is very off-putting. We do the best we can with the technology available. To expect a product that was designed five years ago to be as capable as a newer model is ridiculous given the pace of technology advancement. A computer built five years ago would've been considered state of the art if it had a 1TB hard drive. Now those are considered midrange.
In the next 6 years, when I retire, I plan to go on the road permanently. Therefore, a rack unit like I have now will not work. I'll go to a floor model type. Who knows what will be available then.