Where can I access added Chrome plugins?

[jamc]

I have added a few Chrome plugins but they do not appear in Tools>Plugins Page... can I access the new plugins somewhere to adjust their properties/options?

[The_Solutor]

Likely you mean extensions, not plugins

There isn't a menu entry for this (yet)
You can use

vivaldi://extensions

or
vivaldi://chrome/extensions

in the address bar