SparkFun Pro Micro assumes 16 MHz clock for both 3.3V and 5V variants

[whatthehecker]

(I am pretty new to the whole Rust ecosystem so please bear with me if I am overlooking something obvious)

The SparkFun Pro Micro, just like the SparkFun Pro Mini has a 3.3V/8MHz and a 5V/16MHz variant. For the Pro Mini, there's two different feature flags (sparkfun-promini-5v and sparkfun-promini-3v3) which result in different clock speeds in clock.rs:

        feature = "sparkfun-promini-5v",
        feature = "trinket-pro",
        feature = "nano168",
    ))]
    pub type DefaultClock = avr_hal_generic::clock::MHz16;
    #[cfg(any(feature = "trinket", feature = "sparkfun-promini-3v3"))]
    pub type DefaultClock = avr_hal_generic::clock::MHz8;

In contrast, the sparkfun-promicro flag does not differentiate between the two variants and always assumes a 16 MHz clock.
It seems as if both variants are meant to be supported, since boards.toml explicitly mentions both versions:

[promicro.usb-info]
    port-ids = [
        { vid = 0x1B4F, pid = 0x9205 }, # 5V
        { vid = 0x1B4F, pid = 0x9206 }, # 5V
        { vid = 0x1B4F, pid = 0x9203 }, # 3.3V
        { vid = 0x1B4F, pid = 0x9204 }, # 3.3V
    ]

Treating both variants the same seems to be incorrect, the 3.3 V variant has a 8 MHz clock and should be treated differently than the 5V variant (SparkFun boards.txt which mentions this difference here).

Should both variants be behind different feature flags so they are treated differently?