I know it sound crazy but I’ve tested it enough amount of times to find it’s related. So:
each time I use BoxEdit it makes screen rotation using 3D Mouse very slow and jumping. Restart resolves the problem until the next use of BoxEdit.
Hello - is this always the case? Even in a very simple file? So far (quick test) I do not see it here.
-Pascal
Hi Pascal
Sorry for late response, Weekend starts earlier in Europe 
I have tested this on three files: large (>200MB), medium (>20MB) and newly created, that contains one box only. It is the same behaviour, regardless the size of the file.
No other commands, except using BoxEdit, causes this.
I am using Rhino drivers only for 3d Mouse therefore they are always the latest.
SYSinfo below:
Rhino 6 SR17 2019-7-31 (Rhino 6, 6.17.19212.06361, Git hash:master @ d08a7f69f13c9b9e969c56558b8b779eefa24024)
License type: Commercial, build 2019-07-31
License details: Cloud Zoo. In use by: Piotr ()
Windows 10.0 SR0.0 or greater (Physical RAM: 16Gb)
Machine name: DESKTOP-BNUR9UE
Non-hybrid graphics.
Primary display and OpenGL: Radeon Pro 560X (AMD) Memory: 4GB, Driver date: 6-28-2018 (M-D-Y). OpenGL Ver: 4.5.13521 Compatibility Profile Context 24.20.11016.8001
OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
Redraw scene when viewports are exposed: On
Anti-alias mode: 8x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: Height
Vendor Name: ATI Technologies Inc.
Render version: 4.5
Shading Language: 4.50
Driver Date: 6-28-2018
Driver Version: 24.20.11016.8001
Maximum Texture size: 16384 x 16384
Z-Buffer depth: 24 bits
Maximum Viewport size: 16384 x 16384
Total Video Memory: 4 GB
Rhino plugins
C:\Program Files\Rhino 6\Plug-ins\Commands.rhp “Commands” 6.17.19212.6361
C:\Program Files\XirusCAD\1.0.2.0\v6\Xirus.rhp “XirusCAD”
C:\Program Files\Rhino 6\Plug-ins\WebBrowser.rhp “WebBrowser”
C:\Program Files\Rhino 6\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 6\Plug-ins\RhinoScript.rhp “RhinoScript”
C:\Program Files\Rhino 6\Plug-ins\RhinoBonusTools.rhp “Rhino Bonus Tools”
C:\Program Files\Rhino 6\Plug-ins\IdleProcessor.rhp “IdleProcessor”
C:\Program Files\Common Files\McNeel\Rhinoceros\6.0\Plug-ins\CreateQuadMesh (5bf6c0f3-3657-4ad5-834a-bbbb52706a40)\6.0.6914.24116\CreateQuadMesh.rhp “CreateQuadMesh” 6.0.6914.24116
C:\Program Files\Rhino 6\Plug-ins\RhinoRender.rhp “Rhino Render”
C:\Program Files\Rhino 6\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 6.17.19212.6361
C:\Program Files\Rhino 6\Plug-ins\rdk_ui.rhp “Renderer Development Kit UI”
C:\Program Files\Rhino 6\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 6\Plug-ins\Alerter.rhp “Alerter”
C:\Program Files\Rhino 6\Plug-ins\RhinoCycles.rhp “RhinoCycles” 6.17.19212.6361
C:\Program Files\Rhino 6\Plug-ins\Grasshopper\GrasshopperPlugin.rhp “Grasshopper” 6.17.19212.6361
C:\Program Files\Rhino 6\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 6.17.19212.6361
C:\Program Files\Rhino 6\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 6\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 6\Plug-ins\Calc.rhp “Calc”
C:\Program Files\Rhino 6\Plug-ins\NamedPositions.rhp “Named Position”