Some Chinese guys have worked out pretty perfectly for Mechrevo Z2 which is using the same Tongfang gk5cn6z as in the overpowered 15+. The hardware is almost, if not perfectly, identical: 8750h + gtx1060 + HM370 + intel ac 9560 + ALC269VC + I2C Tpad. Their bios and ec can be flashed onto overpowered 15+. (Their latest bios has more options than op15's, but it throttles the CPU more.)
They were able to get everything working in Mojave (after replacing the wifi card by DW1560), except the GTX1060 (not because there's no Nvidia web driver for Mojave, they mentioned the motherboard makes that impossible yet). No GTX1060 means no external monitors. The iGPU works after disabling the GTX1060.
Simply replacing with their EFI, the keyboard, usb, ethernet, IGPU and sleep work. The rest (audio, trackpad, battery, etc) doesn't work. I tried flash their bios and ec, no improvement. I don't know why, the hardware seems exactly the same.
If you are interested, here's their latest EFI:
https://drive.google.com/open?id=1CKDKafwRkKc4UFJ5Di72upjpLCt0RMB2
I do not game on pc but I bought op15+ for the cpu (and price of course) and the great chasis/form factor. The cpu scores about the same or slightly better than the i7 in 2018 Mac mini in Cinebench (I got 1250 in win10). The mini has more ports and native Apple support, but this laptop has gtx1060, expandable storage, 144hz screen, and lower price.
