Yes. There were many demands from user who wanted decreased spacing between dials.

You mean, that you set your bg color here:

and when you restart browser, this color changes?

Could you please mare screen recording or attach screenshots of what's happening on your FF 58 ? 

Can you please show us what exactly do you mean? My bookmark bar is always on its place

Hello! We will add it to our discussion task. Thank you!

Hello! Unfortunately, there is nothing we can do. New Firefox 57+ doesn't allow us to change imediately Start page. That's why you see Home page first, and then our addon.

Hello! Your bookmark panel is hiding every time you start browser? 

You just need to turn it on and bookmark bar will stay there forever.

Hello!

Widget support is no longer available. We intentionally removed this function from extension

Turn off these options:

And your dials will look like this:

Установил Chrome последней версии (64 версия)

Установил Speed Dial с Хром магазина

У меня есть эти превью изображения.

Можно поинтересоваться, для какого сайта Вы хотите получить превью. У Вас их вообще ни для одного сайта нет?

Можем попробовать team viewer сессию ? https://www.teamviewer.com/