I've ony worked on one system - they removed the old safes completely and just used drain PVC 90 fittings at the bottom. The genius who did the retrofit just hard-plumbed it all, and when a motor failed and it all clogged up I cut the PVC and used rubber couplers to reconnect it so it could be serviced easily if it clogged again.
You want to use hose or rubber flex-conduit anywhere there are bends (after the first 90 under the meter box). The
coins will eventually smash through even Sch. 80 PVC and gray conduit sweeps.
If I did this, I'd still want a safe with the PVC 90 inside.