You can use Neovide in other programs as editor, this page aims to document some quirks. Support for that, however, is only possible as far as reasonably debuggable.
Note: We do not endorse nor disrecommend usage of all programs listed here. All usage happens on your own responsibility.
In your configuration file:
editor: "neovide --nofork"
jrnl saves & removes the temporary file as soon as the main process exits, which happens
before startup by forking.