I've tried various free and non-free software to help me arrange furniture in my house, but they often have features I don't want, while limiting what I can do. I keep coming back to Inkscape as being a possible 2D floor planning tool.

I don't need 3D rendering and walkthroughs. I don't need specific models of furniture, just basic shapes to represent chairs, tables etc.

I use layers to represent rooms. The Measure Segments LPE shows me the dimensions. Pages can represent the first floor etc.

Some things that would make things much easier would be:

1. Ability to lock certain attributes of an object, such as height and width, while allowing others to be changed. This would enable me to have the room shape set up and locked, and the furniture blocks created, without worrying about accidentally resizing a shape.
2. Creation & Editing of  simple shapes in a table. This would be very nice, to be able to paste a table of furniture sizes, and then to be able to edit the sizes, positions, labels etc. Having a table of data related to the current selection, and then being able to edit the height, width, position etc.

Does anyone know of any extensions or tricks that could help here?

I often use CAD for this type of work. FreeCad and Fusion 360 (personal) are good choices, since they are parametric and colors can be assigned to objects.

If I need to collaborate with others on floorplans, I use Google Slides, with a floor outline on the first slide, and duplicate slides used for versioning. I can group text with shapes to label objects. It is easy to switch between slides to compare versions. All in realtime with unlimited participants.