`v$gz` will insert a newline
If you do a visual block from the middle of the line to the end of the line with v$ and then invoke gz, a spurious newline gets inserted at the beginning of the replacement text.
Sounds like you're running into a conflict with the default keymappings. You can disable them and configure another set as makes sense for you. I've kept the defaults as they are in the plugin, but personally I use
let g:titlecase_map_keys = 0
nmap <leader>gt <Plug>Titlecase
vmap <leader>gt <Plug>Titlecase
nmap <leader>gT <Plug>TitlecaseLine
Hope that helps. Closing now as I don't think there's anything to change in the plugin itself here.
Sounds like you're saying you can't repro? You tried it, right? I'm pretty sure it's a bug.
I tried your mappings. Same thing
Ahh, got it. Yes, I'm able to reproduce now, sorry for misunderstanding.
It looks like including the newline character at the end of the line causes the issue. v$<leader>gt causes it, but v$h<leader>gt (addition of the h to move back off the newline / eol) behaves as expected.
Reopening now based on my new understanding.