It seems that the plugin don´t get any updates soon. Since 2016 there are some changes but they only cosmetic. Every year the developers say it will come a big update but nothing happen.

by far, this is a very nice addon but it get not enough love. For me is the color picker broken and i can´t use the reservation thing because it fails to load or save the chnges within the admin panel.

So after one year i will say the 37 Dollar a way to much for this addon and the "big plans" of the developer.

I will now search another plugin what get all the love from the developers...