The PID settings are Gimbal/Controller/Camera/Lens/even FW dependant. Unless Align is using BaseCam controller, it is unlikely that there is any correlation between the PID values.

LPF is low pas filter 42 Hz. On Basecamp there is IMU filters under advanced and filtering tab (32 bit controller)

The BaseCam autotune works reasonably good. just give it a try, tuning one axis at the time, starting with good stability settings.

Yes, but why would you want to? (See the filters tab, the LPF filters are there for each axis, but only on 32 bit boards.)

I do not know what is exactly the difference between the filters tab filter and Gyro LPF under Advanced. The Gyro LPF might be more what the LPF_42Hz is, but BaseCam Gyro LPF does not have direct Herz reading, instead just 0, 1, 2, 3 One needs to try what works best. (or at least it was not Hz reading when I used it in some much older FW)

But before doing any filtering, there should be need for it, so why would you want to use the LPF_42Hz kind of filter? It could be useful for killing vibrations on some big gimbals, that was how I used it, but at that time other filters where not available.

Do you have 32 bit board? if so try the filtering. I recommend using the band pass filters, but why not try the LPF too.