Some devices are improperly detected on Linux as being rotational (ie: hard-drive with spinning disks) when, in fact, the device is an SSD (flash type) device. mkfs.btrfs checks:
/sys/block/DEVICE/queue/rotational
where DEVICE is a block device (sda, sdb, etc…) and if the contents of that file is 1, then mkfs.btrfs considers that the device is rotational and disables SSD features.
In case mkfs.btrfs disables SSD features but you are certain that the device is an SSD, you can simply:
echo 0 >/sys/block/DEVICE/queue/rotational
where DEVICE is the block device, in order to make the kernel treat the device as a non-spinning disk.
After that, you can issue mkfs.btrfs with your favourite options and mkfs.btrfs will detect the device as an SSD.