the option 'Execute blocks' gives you the option to pick and choose which blocks to execute. When you pick a block Omniscope will execute everything upstream of that block, therefore you can pick the last link in a chain.
If you have projects containing multiple Report blocks with visualisations, then 'Refresh all report blocks' is performing an equivalent command that will execute multiple blue blocks in your project, triggering execution of all the blocks upstream.
In the screenshot below if you choose that command the two blocks in the red rectangle shape, which are unrelated to the visuals, will not be executed.
From 2022.1 Rock build - you can now also set within the Report to auto-refresh on open. See Report Settings > Global tab > Auto-refresh section.