Thunderbird 64bit

See: https://portableapps.com/node/24371

You need to produce a convincing business case to the PortableApps Developers, including examples of the tangible and measurable performance benefits that would be gained by users if you expect a 64-bit version of an app to be added to an existing 32-bit version, i.e. not just that it would be great to run a 64-bit app on a 64-bit OS with little or no performance benefit. Don't be fooled by commentators who say/insist that 64-bit software is invariably 'better' without providing any concrete evidence of real benefits.

If Microsoft, goes down the route of dropping support for 32-bit software in the same way that Apple and some Linux Developers have already announced for their future OS versions then maybe you will see change, but that seems to me to be more about OS Developers reducing their support costs/complexibiilty issues and also, for commercial suppliers, pushing future hardware sales than genuinely improving software performance for users.