It is only relevant if you are into this hobby at your level as a Dap surgeon
I had that "oh but it does have dual battery" thing too many times now.
Who cares how many batteries it has. Its not some sort of miracle making it an unbeatable dap.
Its just a well performing dap in its tier with its own pros and cones like any other
It does not outperform pricier R8 or by a long shot SP2000 when it comes to sound performance.
It might contribute to battery life as you said. But if having 2 batteries means it has to be as big as it is this is not a massive feat is it. R8 has the same battery life while being smaller, just heavier.
I am only talking from a perspective where dap sound performance first and foremost than it has to be portable otherwise just get dx300Max or other desktop gear.
I understand there are people who need big screen to listen to music. Or need 4no cyrrus dacs to run whatsapp or facebook videos.
But the way i see it. Dx240 is how dx300 should have been released lol.