Does anyone have any info about when/if Trezor plans to integrate shielded addresses?
It’s simply not feasible at present as it takes circa 3GB of memory. With the planned improvements to Sapling this could be down to around 30MB which would obviously make it feasible for a mobile phone. However one of these hardware wallets is a different matter, the only info I could find was on the Ledger Nano S and Blue (via https://www.reddit.com/r/ledgerwallet/comments/63kgsa/limited_memory_on_nano_s_same_limits_for_the_blue/) and they say:
Nano S has 320 Kb flash, 10 Kb RAM, Blue has 480 Kb flash, 12 Kb RAM (less available for applications after the OS is installed)
So assuming Trezor is in the same ballpark it’s unlikely these current devices will support it in the foreseeable future. Long story short you likely won’t get a clear roadmap of support for any devices until the Sapling upgrade rolls around.