I think I never mentioned in the forum, but last year I ordered one or two of these from taobao:https://world.taobao.com/item/42336448586.htm
It was the only cheap board I could find with an RFT mcu, so it was supposed to have 768KB of flash, but with stlink I tested I could read and write up to 1024KB of flash, so similar to extra found in x8 and xC mcus.
I still have not seen the board pop up in aliexpress, not sure why since it is cheap and small, and so far has no competitors with that flash size.
It includes an eeprom. In the page it says it's a 24c512, I'll confirm when I get home.
Also has a 32khz xtal. I have not tested it for accuracy, neither the multiple peripherals, but if I remember right I loader the bootloader to one of them and used a small serial sketch to test it.
There is a power led and a reset button, but no user leds or buttons.
I just added a page to the wiki.
I think I'll use this one to test the program Pito has been working on, to jump in and out of a 2nd program in RAM, since this has 96KB of ram, so I'll post more results of testing it.