Your comments
You can achieve this easily with the following external tool:

Will be part of the next SmartGit 20.2 preview.
Sorry, 32-bit is not supported any more with the latest version (the essential third party library SWT does not support it any more).
Please try SmartGit 20.1 build 15143 (Help | Check for Latest Build). There is a new low-level property fileSearchOrFilter.matchInside.
A lot of shortcuts (those available in menus) you can reassign: Edit | Customize. Unfortunately, this does not apply to hardcoded ones for special controls.
Hm, Ctrl+Y is mapped to Delete Line.
Could you please describe in more details what exactly you expect from this feature? Thanks in advance.
The current behavior was intentional because otherwise it would become much easier for users to open all their hundred repositories and then might wonder why SmartGit gets so slow and memory hungry.
Customer support service by UserEcho
Either select the branches in the Branches view or the commits in the Graph view before invoking this tool from the context menu.