@Medeman If uBlock can do it, the internal blocker can as well. It's just a matter of figuring out what URL(s) to block. The internal blocker can use the same lists as uBlock, so probably you won't even need to make your own list, just figure out what list to add.
You need to look at the network tab in DevTools to get an idea what to block.
Do you have a link to a channel with a lot of such ads?
EDIT: From a quick look at Twitch, looks like it uses amazon-adsystem.com to serve ads. This is already included in the list "English (Peter Lowe's List)" which Vivaldi includes. You might just need to enable it.