The S0 and S2 security is not likely relevant here. There is no issue with having S0 and S2 devices on the same network in general, Z-wave protocols are designed with backward compatibility in mind.
due to lost packets
Your system does not show messages being dropped in diagnostics. All devices show a good connection to neighbor nodes.
or having to amplify its signal
Z-wave locks do not do this. It can’t amplify strength levels, and the lock only reports two repeaters as neighbor nodes, the panel itself is not a direct communication option for it.
The issue here is almost certainly going to be one isolated to the lock.
Please try a removal and re-inclusion of the lock. I would also suggest a factory reset the lock during that process. To reset:
- Remove the battery pack.
- Hold down the program button
- While holding the program button down, slide in the battery pack
- Keep holding the program button for about 30 seconds, the lock will beep and flash red when ready. Release the button.
- Press the program button one more time. The lock will beep and flash green.
Another thing that might chew through batteries quickly is difficulty of the lock motor to engage or disengage the lock. This can happen if the lock is overtightened or a bit misaligned.
That’s actually easier to do than you would expect, as the typical manual handle lock or deadbolt has much more tolerance for variation than a motorized lock. This is a much more common occurrence in deadbolts though.
You can certainly try a different or additional repeater, but I do not expect it would make a difference. 2 weeks battery drain is indicative of an issue outside of normal signaling.
Older models of plug in appliance modules like the Zw4101 might be available used, but I am not aware of current models using only S0. Newer devices support both S2 and S0.