bottom line here is that when i map "+y to <c-i>, it dos not work in visual mode. below are the specifics.
Here is output of 'version' :version VIM - Vi IMproved 8.0 (2016 Sep 12, compiled Sep 30 2017 18:21:38) Included patches: 1-197, 322, 377-378, 550, 703, 706-707 Modified by pkg-vim-maintain...@lists.alioth.debian.org Compiled by pkg-vim-maintain...@lists.alioth.debian.org Huge version without GUI. Features included (+) or not (-): 1. enter ':vmap <c-i> "+y<cr>' (to map the visual mode yank) 2. in blank screen, hit 'i' key (for insert mode) 3. enter 'now is the time<cr>'. 4. hit <esc> key 5. hit 'v' key (for visual mode) 6. hit 'k' key to select the text 7. do <c-i> ( actual result is that editor stays in visual mode; expected that it would return to normal mode) 8. hit 'v' key to exit visual mode 9. hit 'j' key to move to next line 10. hit 'p' key to put the selected text (actual result is no change; expected that editor would put 'now is the time' in the document)