While I'm mainly an emacs user, I do enjoy using mg from time to time. Especially nice that it comes with macOS nowadays (used to come with age old emacs version). I could probably do everything in mg, but I just cannot stand the auto indendantion in it when you have 8 spaces of indent and write a newline, the next line gets auto indented with a tab instead of 8 spaces (newline-and-indent assumes tabs are every eight characters..) Sure, this is not an issue if you use only tabs, but most projects just tend to be using spaces. Also, I think in OpenBSD mg there is a flag for enabling/disabling this (IIRC).

Nonetheless, I do like mg!

I prefer -vi- defaults so:

    au!
    
    set noai
    set sm
    set cp
    setf none
    set nocindent
    set nosmartindent
    filetype off
    
    inoremap <Left>  <NOP>
    inoremap <Right> <NOP>
    inoremap <Up>    <NOP>
    inoremap <Down>  <NOP>
    
    noremap <F1> <NOP>
    inoremap <F1> <NOP>
    
    cabbr h you_typed_colon_h_again_you_idiot
    
    nnoremap q <NOP>
    
    autocmd FileChangedShell \* echon ""
    
    set directory=/tmp
    
    set mouse=
    set ttymouse=
    
    # try uncommenting this if angry fruit salad still ensues:
    # syn off