What the 32 MHz Cortex-M0+ means for your BOM
The STM32L072RBT6: It carries an additional 6 K x 8 EEPROM for parameter storage without external parts.
Flash and RAM sizing — firmware headroom
128 KB of program Flash gives room for a moderate RTOS, a USB stack, and application code. The 20 K x 8 SRAM handles a few KB of stack plus a couple of large buffers — enough for a sensor fusion algorithm or a small display framebuffer. If your firmware pushes past 100 KB, look at the 192 KB or 256 KB Flash variants in the same L0 family; they share the same 64-LQFP footprint.
Package and rework — 64-LQFP
The 64-LQFP (10x10 mm body) is a standard fine-pitch gull-wing package. It reflows cleanly with a standard lead-free profile; the exposed pad is absent, so you don't need a bottom-side heater. The tray shipping medium is fine for low-volume builds; for reeled tape, order the 'TR' suffix variant.
Lifecycle and supply posture
ST lists the STM32L072RBT6 as Active. For dual-source resilience, the STM32L072xx family includes pin-compatible density variants that share the same 64-LQFP footprint — a straightforward BOM alternate if firmware fits.