Just for your information about ChromeOS/ChromiumOS :
Jingling and FydeOS share the same shareholders, a discussion : https://www.reddit.com/r/JingOS/comments/nfnkrd/what_does_jingteam_think_about_fydeos_for_the/
Years go by, Sh*tstarter campaigns continue to rake in tons of cash. "Selling you stuff you either don't need, or already have, and at just $549!". If 2000's were gangsta's paradise, 2010's is grifter's.
Eh, 4xA75's is usable, especially without the proprietary Google bloatware. But you'd only be buying this for the OLED screen, which seems to have a random number of pixels, and it has no guarantee to support L1 Widevine. And there are also other OLED tablets by Lenovo and Samsung in this price range.
Jingling has confirmed the price of the JingPad A1, the 2-in-1 convertible running a Linux-based tablet OS. The JingPad A1 features a Unisoc Tiger T7510 SoC though, so the tablet may offer limited performance.