There're some parameters that do not have a GUI element to enable/disabled them, so you'll need to set them using the terminal.

Just open the Terminal.app and write this:

defaults write com.aone.keka <PARAMETER> -bool <TRUE/FALSE>

• ForceOldQueue: Use the old queue system. Disabled by default. Obsolete in 1.2.0 and newer.
• Take a look at the verbose parameters.

• Use7zz: Use 7zz instead of p7zip. Enabled by default since 1.2.51.
• UseMultithreadLzip: Use plzip instead of lzip. Enabled by default since 1.1.9.
• UseMultithreadPbzip2: Use pbzip2 instead of lbzip2. Enabled by default. (Since 1.1.0-beta.r2466 #147).
• UnrarWithP7ZIP: Use p7zip instead of unrar for RAR extraction. Disabled by default. (From 1.1.18).
• ForceHFSDMG: Force HFS+ and HFSX instead of APFS when creating a DMG for better compatibility with Mac OS X 10.11 and older. This only affects macOS 10.12 and newer. Enabled by default. (Since 1.0.15 #159).
• UseISO9660: Use ISO966 instead of UDF when creating ISO volumes, for legacy purposes. Disabled by default. (Since 1.2.57).

• Legacy19007zSupport: Create 7Z files compatible with 19.00 version. Disabling it can use more advanced compression methods from 23.00+ versions but can render files incompatible with non updated extraction tools. Enabled by default since 1.4.1.
• ZipUsingAES: Use AES256 when creating a password protected ZIP. Disabled by default. This file is only supported on macOS 10.15 or newer or with a third party app (like Keka 👍).
• ExportPassword: When compressing with a password set, this option will generate a TXT containing the password near to the compressed file and with the same name. Disabled by default. In honor to Sean.
• CalculateMD5: After a successful compression a file containing the MD5 checksum will be generated near the compressed file. In honor to Atomlin (Since 1.2.14).

• UnzipWithUNAR: Use UNAR instead of p7zip when extracting most ZIP files. This is a bit slower but is more old-encoding friendly (#12) and respects forks and metadata (#138, #293 and #294). When extracting certain ZIP files, for example those created with p7zip, this setting will be ignored. Enabled by default. (Since 1.1.16).
• IgnoreGZIPName: Ignores original file name when extracting GZIP files (using p7zip). Disabled by default. (Since 1.2.0-dev3846, #82)
• SkipQuarantineSlowdownDetection: Do not detect quarantine application slowdown issue. Enable this option in very slow systems/disks if you're wrongly receiving the slowdown message. Disabled by default. (Since 1.2.53, #1040)

• UseGrowl: Use or don't notifications. Enabled by default. Since v1.1.0, Growl is no more used for notifications. The parameter will stay with this name for better legacy compatibility and to show gratitude to the Growl project. This parameter has it's space in the GUI, but since the introduction of Notification Center was removed. It may get it's space again, after all.
• GrowlBlocksExit: If UseGrowl is enabled, Keka waits a few seconds before quitting so the notification action can be triggered. Disabling this will render the notification actions unusable in some cases. Enabled by default.

If you think some of this options should be in the GUI, let me know via the Issues section.