I'm presuming you've seen the AD
Of interest may be what
laterite is.
Probably hard to get away from it anywhere in Aus or anywhere between the 2 tropics!
This AD has been around for a while and the latest one covers the determination that the issue may be worse than expected.
Determining how much cr@p the engine has eaten and vibe checks are the solution until TU 360 is incorporated.
The rear gas generator bearing is a sensitive area on the Arriel and needs to be looked after appropriately.
First point - don't operate the engine like an Allison 250!