Team Win Recovery Project 3.x, or twrp3 for short, is a custom recovery built with ease of use and customization in mind. Its a fully touch driven user interface no more volume rocker or power buttons to mash. The GUI is also fully XML driven and completely theme-able. You can change just about every aspect of the look and feel.
Formatting Data (Sometimes it errors out after wiping data but it can be fixed by rebooting and trying again.)
Vibration (Low priority)
SD card (Should be possible to mount it manually for now)
For now I'm using the GSI, but I do want to eventually port LineageOS to it (I have only little experience so this could take a long time). I'd also like to get mainline Linux booting on this tablet, since SD865 is supported in Linux and SD870 is an overclocked SD865.
EDIT: I've been using the GSI for some time now and the performance is great. I'll try looking into the issues the GSI has because if the GSI works good there's no need to make a new and seperate LineageOS port. I would need to learn how to do that first though so it can take some time.