
The previous snapshot based on Chromium 54, which has offered Search with context menu option, has text blurriness and focusing issues. These issues along with other bugs have been fixed by the Vivaldi team with the snapshot 1.5.644.7.
This snapshot has improved tab dragging between Windows and brings in more access options for Reader View aka Reader Mode. The Toggle button which has been provided in the address field is one, those who’re keyboard focused, can now assign shortcut for Vivaldi reader view, Here is how that can be done.
Assigning or creating a keyboard shortcut for Vivaldi Reader View
Click on V menu > Tools > Settings > Keyboard, scroll down and expand Page section for the so far assigned shortcuts to be displayed.
In the Toggle Reader View field, type desired shortcut (single key shortcuts won’t be allowed by default).
For instance, you can use Alt +R shortcut, which is the same one Mozilla has assigned to Firefox Reader View. Ensure the cursor in the input field is highlighted, hold the ‘Alt’ button and press ‘R’ button on the keyboard.

Note: Unfortunately, Reader View isn’t working as expected for many sites, test the keyboard shortcut you’ve assigned above by visiting the Wikipedia site in the Vivaldi browser.
You can download Vivaldi snapshot 1.5.644.7 for Windows and Linux (not available for Mac) from here.
Has this snapshot fixed the blurriness issues you’re having with Vivaldi? Let us know in the comments.