For anyone who'd also like this, I have a flaky workaround for a very specific need I have - wanting to open multiple repos in a single windows terminal window. I only have one custom action for this very purpose:

After creating this, open the repo tab you want in source tree.
By default, my tab does not select any files and just highlights this:

This may be important as it could mess up the next bit.
The bottom of my Actions menu looks like this here:

From here with the sourcetree window in focus, hit the following keys in this order, not all together:
Alt, A, Up, Enter and Enter again.
Assuming you only have one customer action, it should have just activated.
If you have multiple you can move up/down before hitting the final Enter to select from them.
This is far from ideal but with some muscle memory it'll work for me.. although I'm having a hard time justifying using sourcetree as-is since I prefer my own powershell aliases to run git commands.
I've also heard this tool is good for automating certain keypresses so might help here: https://www.autohotkey.com/
Please just add proper shortcut controls.
Edit: my image uploads have been blocked (for review?) unfortunately.
For anyone who'd also like this, I have a flaky workaround for a very specific need I have - wanting to open multiple repos in a single windows terminal window. I only have one custom action for this very purpose:
After creating this, open the repo tab you want in source tree.
By default, my tab does not select any files and just highlights this:
This may be important as it could mess up the next bit.
The bottom of my Actions menu looks like this here:
From here with the sourcetree window in focus, hit the following keys in this order, not all together:
Alt, A, Up, Enter and Enter again.
Assuming you only have one customer action, it should have just activated.
If you have multiple you can move up/down before hitting the final Enter to select from them.
This is far from ideal but with some muscle memory it'll work for me.. although I'm having a hard time justifying using sourcetree as-is since I prefer my own powershell aliases to run git commands.
I've also heard this tool is good for automating certain keypresses so might help here: https://www.autohotkey.com/
Please just add proper shortcut controls.
Edit: my image uploads have been blocked (for review?) unfortunately.