Obviously TGC have to find a solution that fits all.
I can think of four possible options, as follows:
1- Perhaps one floating toolbar would help.
The bar appears when you select the entity.
The meaning of the buttons is the same as in the gizmo menu.
2- Add an option called Gizmo in the main toolbar menus.
3- Add a new tab called Gizmo and locate the buttons on it.
4- Add these buttons directly on the main toolbar (above).
The latter does not seem the most appropriate, since GG is expanding, and TGC is keeping free space for the new buttons they could need.
On the other hand, adding to the left tabs the option to hide / show, would help save space in the editor.
Just my thoughs
Note: Please do not mind about the quality of the icons, they were made quickly to show my idea.
3com
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