Make YouCompleteMe open definition in vertical split even if buffer is not saved

Question

There is something I cannot do with YouCompleteMe that I could do when just using tags to navigate to a definition or declaration.

The desired behaviour is (taking into account that , is my leader key):

1. ,g should attempt to go to the definition/declaration in the current buffer. If changes to the buffer are not saved, it should print an error "No write since last change" or something similar and do nothing.
2. ,ds should open the definition/declaration in a vertical split, regardless of whether changes to the current buffer have been saved or not (since the original buffer will remain open).
3. ,dt should open the definition/declaration in a new tab, regardless of whether changes to the current buffer have been saved or not (since the original buffer will remain open).

With ctags, behaviour 1 was the standard Ctrl], and 2 and 3 could be achieved with:

" Open definition in new vertical split
map <leader>ds :vsp <CR>:exec("tag ".expand("<cword>"))<CR>
" Open definition in new tab
map <leader>dt :tab split<CR>:exec("tag ".expand("<cword>"))<CR>

However, YouCompleteMe seems to behave differently. According to the official documentation:

The g:ycm_goto_buffer_command option

Defines where GoTo* commands result should be opened. Can take one of the following values: [ 'same-buffer', 'horizontal-split', 'vertical-split', 'new-tab', 'new-or-existing-tab' ] If this option is set to the 'same-buffer' but current buffer can not be switched (when buffer is modified and nohidden option is set), then result will be opened in horizontal split.

This means that if I define my new mappings as:

" Shortcuts for navigating to definitions using YouCompleteMe
map <leader>g  :YcmCompleter GoToDefinitionElseDeclaration<CR>
" Open definition in new vertical split
map <leader>ds :vsp <CR>:exec("YcmCompleter GoToDefinitionElseDeclaration")<CR>
" Open definition in new tab
map <leader>dt :tab split<CR>:exec("YcmCompleter GoToDefinitionElseDeclaration")<CR>

I can't achieve any of the behaviours if the changes to the file have not been saved:

1. ,g does not print an error, but instead opens the definition/declaration in a new horizontal split.
2. ,ds does not open the definition/declaration in the new split directly, but instead creates the vertical split and then opens the definition/declaration in a horizontal split inside the vertical split.
3. ,dt does not open the definition/declaration in the new tab directly, but instead creates the new tab and then opens the definition/declaration in a horizontal split inside the tab.

What settings/mappings should I set to achieve the desired behaviour?