You are completelly correct. However it was already fixed :-)

Further investigations provided: INI value 'ToolbarsLayout' must be to long. By shifting the strings inside it I could determine that everything beyond byte 2048 isn't interpreted.

ReadPrivateProfileString() from Win32 API supports actually any value length but diverse class libraries using this func limit their input buffers: f.i. MFC reads maximally 512 chars into CString, don't know how large the buffer in BCL is. You may consider splitting the setting into different keys or using Win32 directly.

Yours

Apparently it's loading of INI what fails:

[Configuration\Interface\Commander]
ToolbarsLayout=LocalHistory_Visible=0,...

inserted manually is ignored and reset by WinSCP to:

ToolbarsLayout=LocalHistory_Visible=1,...

No matter how you rearrange the toolbars in the local panel (Commander style), they will ALWAYS be in the initial state (each toolbar in its own row) on next prog start, even hiding a toolbar doesn't survive.

Please refer to this in the next stable as INI is quite important option in order to run the prog from removable media.