Trackpad does not load bcm5974 module.

[sleekweasel]

So having installed the rozza/master branch, and having copied the modules to lib/modules/4.15.0-33-generic/kernel/drivers/hid, and having rebooted, I'm not seeing bcm5974 in lsmod - I presume simply connecting the device should bring that in, independent of X? (X is running post-reboot, and the config file is there, but I'm only getting move+click basic functionality)

[ 2591.066581] hid-generic 0005:004C:0265.0005: unknown main item tag 0x0
[ 2591.066710] input: Magic Trackpad 2 as /devices/pci0000:00/0000:00:14.0/usb1/1-7/1-7:1.0/bluetooth/hci0/hci0:256/0005:004C:0265.0005/input/input20
[ 2591.067274] hid-generic 0005:004C:0265.0005: input,hidraw3: BLUETOOTH HID v0.62 Mouse [Magic Trackpad 2] on 34:e1:2d:84:98:b4

Running sdptool browse shows this:

sdptool browse 64:A5:C3:F1:85:DE

Browsing 64:A5:C3:F1:85:DE ...
Service Name: Magic Trackpad 2
Service Description: Trackpad
Service Provider: Apple Inc.
Service RecHandle: 0x10000
Service Class ID List:
"Human Interface Device" (0x1124)
Protocol Descriptor List:
"L2CAP" (0x0100)
PSM: 17
"HIDP" (0x0011)
Language Base Attr List:
code_ISO639: 0x656e
encoding: 0x6a
base_offset: 0x100
Profile Descriptor List:
"Human Interface Device" (0x1124)
Version: 0x0100

but I can't see any likely-looking numbers to copy into bcm5974.c's device table to try the USB pid:vid trick that often worked with minor USB device updates.

Help?