Rendering panel opens as a toolbar tab

Rendering panel opens as a toolbar tab:

Summary

Rhino 8 SR0 2023-10-9 (Rhino 8 BETA, 8.0.23282.01003, Git hash:master @ 8cfe3fd8436e6ddefaaf016f6e917eda401222ef)
License type: Educational Lab License, Build 2023-10-09
License details: Stand-Alone
Expires on: 2023-11-23

Windows 11 (10.0.22621 SR0.0) or greater (Physical RAM: 32Gb)
.NET 7.0.11

Computer platform: DESKTOP

Standard graphics configuration.
Primary display and OpenGL: NVIDIA GeForce RTX 2070 (NVidia) Memory: 8GB, Driver date: 4-25-2023 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 531.79
> Accelerated graphics device with 4 adapter port(s)
- Windows Main Display attached to adapter port 0

OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
Redraw scene when viewports are exposed: On
Graphics level being used: OpenGL 4.6 (primary GPU’s maximum)

Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 4-25-2023
Driver Version: 31.0.15.3179
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 8 GB

Rhino plugins that do not ship with Rhino
C:\Program Files\SimLab\Plugins\SimLab 3D PDF From Rhino 6\plugins\SimLabPDFExporter.rhp “SimLab PDF Exporter”
C:\Users\Charles\AppData\Roaming\McNeel\Rhinoceros\packages\8.0\IntelDenoiser\0.6.7\IntelDenoiser.Windows.rhp “IntelDenoiser.Windows” 1.0.0.0

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 8 WIP\Plug-ins\Commands.rhp “Commands” 8.0.23282.1003
C:\Program Files\Rhino 8 WIP\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 8 WIP\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 8.0.23282.1003
C:\Program Files\Rhino 8 WIP\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 8.0.23282.1003
C:\Program Files\Rhino 8 WIP\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 8 WIP\Plug-ins\MeshCommands.rhp “MeshCommands” 8.0.23282.1003
C:\Program Files\Rhino 8 WIP\Plug-ins\RhinoCycles.rhp “RhinoCycles” 8.0.23282.1003
C:\Program Files\Rhino 8 WIP\Plug-ins\RhinoCode\RhinoCodePlugin.rhp “RhinoCodePlugin” 8.0.23282.1003
C:\Program Files\Rhino 8 WIP\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 8.0.23282.1003
C:\Program Files\Rhino 8 WIP\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 8 WIP\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 8 WIP\Plug-ins\SectionTools.rhp “SectionTools”

That is because you’re adding it to the toolbar, so it won’t fit. Either create a new container, or add it to the one on the right where you already have layers, properties, display and help.

That should not be allowed.

And why not? It´s up to you, what to add to any container.

Because it makes no sense to add a panel to a set of toolbars.

Seems I’m too dense to understand the container concept.
I’ll read the manual.