"Changeable primitives" and "Add on top of Grid"

sorry for my English

Proposal #1

Perhaps this proposal does not for all types of objects, but to geometric primitives like cube, sphere, cylinder, etc.

This is an addition to these Proposals:

blender.community/c/rightclickselect/wrcbbc/

blender.community/c/rightclickselect/6Hbbbc/

We need primitives, whose parameters can be changed even after some time after creation. When these primitives satisfy you, you can begin to edit their geometry after converting them into a mesh (Object > Convert to > Mesh). After that you can press Tab and start editing the geometry. Until the primitive is not converted to a geometry, it will remain a primitive with editable parameters.

You can make some of the primitives сhangeable when creating, or all of the primitives in the program settings. You can also make all primitives сhangeable in the program settings, and when creating one, uncheck the "Changeable primitives" checkbox and create the usual ones.

You can change the settings of the primitive in the Object panel. And maybe change the type of object, for example, from cylinder to cube.

Proposal #2

When you create a primitive, it is always in the middle of the grid, along the Z axis. If you are modeling a real object, then it is almost always above the ground level, above the grid. You should always lift primitive up along the Z axis by one meter - G > Z >1.

It would be very useful if the primitive was created at the top of the grid, and move Origin to down of mesh, when it is necessary. If you place a 3d cursor on the surface of the object, then you can create a primitive on the surface of the object, and origin will be on the surface, this is useful for snaping to surface. Like bolts and rivets.

For all objects from settings and for individual objects fron add menu: