What does MultiZilla do with the Bookmark Manager?

When MultiZilla is enabled, two things happen with the Bookmark Manager:

1. A new button, Bookmark, which adds a bookmark. Fine, but it should 
have an icon. I know Modern and Classic do not have icons for buttons 
there, but "all other" themes do. It looks odd. But an option to turn it 
off would be good enough.

2. But this one is worse: No drag and drop. From JavaScript Console when 
trying to move a bookmark by drag and drop:

Error: [Exception... "'JavaScript component does not have a method 
named: "canDropBeforeAfter"' when calling method: 
[nsIXULTreeBuilderObserver::canDropBeforeAfter]"  nsresult: "0x80570030 
(NS_ERROR_XPC_JSOBJECT_HAS_NO_FUNCTION_NAMED)"  location: "JS frame :: 
chrome://global/content/bindings/tree.xml :: onxbldragover :: line 208"  
data: no]
Source File: chrome://global/content/bindings/tree.xml
Line: 208

Error: [Exception... "'JavaScript component does not have a method 
named: "canDropOn"' when calling method: 
[nsIXULTreeBuilderObserver::canDropOn]"  nsresult: "0x80570030 
(NS_ERROR_XPC_JSOBJECT_HAS_NO_FUNCTION_NAMED)"  location: "JS frame :: 
chrome://global/content/bindings/tree.xml :: onxbldragover :: line 208"  
data: no]
Source File: chrome://global/content/bindings/tree.xml
Line: 208
-

Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7) Gecko/20040514 
MultiZilla/1.6.4.0b