Can anyone upgrade Hacker's keyboard?

Can anyone upgrade this Hacker’s keyboard?
It has not been upgraded since 2018.

I need at least left and right arrows to correct typing errors and also (.com) and (/) in 4-row gingerbread layout portrait mode.
Currently only available in 5-row.

1.41.1 from 2018 is the latest version and it’s on F-Droid: https://github.com/klausw/hackerskeyboard/tags