Thank you for your suggestion.
May I please clarify with you if you have tried the OAuth authentication during your project creation in The Welkin Suite? This is available on The Welkin Suite for Windows. We implemented this feature exactly for improving the security of your projects. Your credentials are not saved anywhere in TWS files when you use it.
In the case when you create TWS project with OAuth, as I mentioned, you will be redirected to your default browser, and there you can use the LastPass or other similar applications to store your sensitive data out of The Welkin Suite.
As a side note, even in the case, when you use the usual way to create a project, your credentials are encrypted inside your TWS project file.
Also, we are going to add an ability to use the OAuth Authentication on The Welkin Suite for Mac.