If the stuff inside the CDATA brackets is formatted with tabs, the editor is free to interpret that with the user's settings in mind. Specifically, if the user has a setting to do "tabs as spaces" and "tabwidth = 2" then an autocomplete that is read in as a tab will expand to tabs of width 2 spaces. If they are hardcoded in the sublime package as four spaces, then this will make the editor (when width setting is 2) to interpret it as two tabs (as opposed to the desired effect of one).
If the stuff inside the CDATA brackets is formatted with tabs, the editor is free to interpret that with the user's settings in mind. Specifically, if the user has a setting to do "tabs as spaces" and "tabwidth = 2" then an autocomplete that is read in as a tab will expand to tabs of width 2 spaces. If they are hardcoded in the sublime package as four spaces, then this will make the editor (when width setting is 2) to interpret it as two tabs (as opposed to the desired effect of one).