** update of this blog **
this didn’t work, and it turns out the macbook bluetooth cannot handle intensive shared usage because of limited bandwidth or whatnot. sorry macbook fans. i got a usb mouse instead. my bluetooth keyboard and mouse simply is waste right now.
got a new macbook pro, and guess what, bluetooth seems only work for 1 device. when connecting to my bose QC 35, it works fine, as soon as i hook up my bluetooth mouse, it start disconnecting.
found an article addressing this issue, but it does not work that well.
basically it is turning off
“Allow Handoff between this Mac and your iCloud devices”
https://www.forbes.com/sites/bradmoon/2017/07/13/this-trick-may-solve-your-mac-bluetooth-connectivity-issues/#7fcf16b45196