It still amuses me how few people, even those who claim security expertise, don't understand that commercial malware is able to hook the driver stack (and or browser's network stack) and intercept pre-encrypted HTTPS traffic.
Hooking traffic rather than keystrokes is preferred because in order to resell that stolen data the data needs CONTEXT. A stream of keys is difficult to interpret into anything meaningful at scale, whereas "HTTPS POST Request to URI [xyz] with fields [X & Y] with values [J & W]" is very monetizable.
What I am saying is TreasuryDirect's on-screen keyboard "security" stuff is complete nonsense, it has no technical merit at all. None. Worse still it also hurts users of accessible technologies, touch-screens, or users using password managers (essentially promoting password re-use, a common problem).
Even something as simple as disabling navigation links/buttons after being clicked before the next page load would mostly solve this and save hours of frustration having to re-login through their god awful signin flow every time.
edit - looks like no. On the one hand a single sign on to both would have been nice, OTOH TreasuryDirect's authentication system is a PITA.