I can only say my RME ADI2-DAC v.2 (also OLED AFAIK) has zero burn-in so far, BUT I have "auto dark" enabled, so the display is active only a few seconds when it's needed. If the Topping also has this feature, I would simply enable it.
a 4.4mm jack, & something that looks more professional than* a plastic toy. that's the oled from the d50! i had one, it sucked... just the oled i mean.
I can see that it's time to dig out the After Dark floppies from the back of your PC parts drawer. Although maybe Topping could include a copy of Dazzle. Dazzle was freeware, I think, and wouldn't cost them anything. Topping might have to pay royalties to Grace Slick for the flying toasters!
I read the owners manual and it has auto OFF for the display.
I have the DX3 Pro+ in my current desktop setup. RCA outputs go to a pair of active speakers (iLoud Micro Monitors) and I have a pair of HiFiMan HE400se headphones connected to the 1/8 in jack. The iLoud monitors are great for Zoom calls while working from home, but I kind-of hate how they sound for music; that's where the headphones come in. The DX3 Pro+ makes it easy to switch from active speakers to headphones.
I use a Galaxy S6 Curve that is about 7 years old, still working, featuring an OLED screen. It doesn't have anything like burn-in. So I don't know how it is, generally speaking.
Making a surround receiver is exponentially more difficult than making one of these. Both in terms of resources required and the technical challenges.
those are wildly different screens. the topping is low res (giant pixels) & just white. my d50s had some retention issues after a few weeks of use as primary dac. you can turn off the screen, but then why have it at all?
Marantz Nr1200, although i don't know if it's better performance wise than its sibling Denon HRA800, which didn't measure great at all.
"Sports", can be used as slang for something that has something. It's cool talk! Like my new car is sporting a nice stereo system or she sports a nice car.
I use my Dx7pro for my bedside setup. Raspberry Pi as source for Roon, Bluetooth is convenient for AppleTV. Only headphones.
The vent holes are for dissipating the heat given off by the electronics inside. Some electronics are less efficient than others and so you see some with vent holes and some without. It's a inherent thing about circuit designs that some give off more heat than others.
No worries unless you smell dust burning or plastic melting. 
Really hot for domestic/consumer electronics is about 85C and for the next grade up at 105C and then the next grade goes to about 130C. I worked building downhole tools for measuring in oil well drill holes and they measured up to a calibrated 177C. @ 177C the qualifying of the electronic components had a success rate of about 15% and the rest failed from the heat in the calibrated test oven.
