So far I am pretty satisfied with using eve V. However I have several issues with the pen.
One issue is that the magnet is too weak to fix the pen. It rolls off from the screen really easily. I think however strong the magnet is, the problem will occur anyway as long as grab the screen and use eve.
So I suggest having a physical slider bar to attach/detach the pen. I think this can be manageable with a small side bar on the side of the screen. The slider seems durable compared to U-shaped magnetic holder(sample example here)which tends to break easily.
Off topic, but also the pen issue - when I tried to use the pen, the part of the screen where my palm touches acted crazily. Found out the palm rejection (Ignore touch input when I’m using my pen). Still, it behaved crazily. I uninstalled and re-installed the touchscreen driver, and now it works fine. Probably related to this topic