Since yesterday, the really cool fork of openboard with active development and support of adding a swype library manually, got rebranded into Heliboard. A release on izzyondroidrepo and fdroid should be coming soon.
PS. If you are using the old fork you have to remove it first and do a backup of your settings.
Why security critical?
Any foreground app can read the clipboard on Android. Androids clipboard only stores the last entry, so such clipboard histories in keyboard apps will be in the internal app storage. But as Openboard has no dedicated “copy only to internal clipboard” you have no protection really.