Pi Zero is kind of "minimal spec" for running Kodi and is not ideal for a Kodi workhorse. There are some caching improvements that should improve the GUI navigation in large lists (e.g. library views) due in LE 8.0.1 (with Kodi 17.1). From personal experience an RPi3 with a faster clock speed and more RAM is very daily-useable; although in comparison a 3.5 year old Intel/nVidia box I have is still miles better (was 4x the price of a typical RPi3 kit at the time I acquired it though). Yatse is nothing to do with LE, if that doesn't work it's not our problem
I think you're right, the yaste issue is probaly due to the GUI lags. Direct command (ie update library) are working well.
I liked the idea of running Kodi on the rasp zero. It works well with kodi 16... It was kind of pure. With the rasp zero w, the awfull wifi dongle was deseapering...
Thanks again for the work, I'll follow the update.
PS : I never saw more than 50 % of the memory used on my rasp zero.