RISC-V root device question

All,

The FreeBSD wiki page on RISC-V reads:

If you get mountroot prompt, then indicate to the kernel the location of 
rootfs:

mountroot> ufs:/dev/vtbd0

This indeed appears to be remain the case on CURRENT as of last week.

Specifying a device and partition, or disklabel at the mountroot> prompt 
works every time but none of these do not help in loader.conf (tested 
individually):

cam.boot_delay="100000"
vfs.root.mountfrom="ufs:/dev/vtbd0p3"
vfs.root.mountfrom="ufs:/dev/gpt/rootfs"
rootdev="/dev/vtbd0p3"
rootdev="vtbd0p3"
currdev="vtbd0p3"

Or these in the fstab:

/dev/gpt/rootfs /       ufs     rw,noatime      1       1
/dev/vtbd0p3   /       ufs     rw,noatime      1       1

Are there any other options? Perhaps building the device name into the 
kernel?

Thank you!

Michael