6.0.5 various fixes

[jamesdaniels]

Checklist

• Issue number for this PR: #nnn (required)
• Docs included?: (yes/no; required for all API/functional changes)
• Test units included?: (yes/no; required)
• In a clean directory, yarn install, yarn test run successfully? (yes/no; required)

Description

Code sample

[jamesdaniels]

@alx-andru I was inspired by your work in #2608, thanks! I decided to implement the API as null properties on the .prototype, I generate the properties via ts-transformer-keys at build time. It's a little magic but it seems to work well enough.

[google-cla]

A Googler has manually verified that the CLAs look good.

(Googler, please make sure the reason for overriding the CLA status is clearly documented in these comments.)

ℹ️ Googlers: Go here for more info.

[googlebot]

A Googler has manually verified that the CLAs look good.

(Googler, please make sure the reason for overriding the CLA status is clearly documented in these comments.)

ℹ️ Googlers: Go here for more info.