How to handle domains when they are put into a pseudo-redemption state.

[Head Boy]

I'm an authorised domain registration reseller, and about a year ago I started to register domains for adult biz newbies with restricted methods of payment. Those domains are now coming up for renewal, and I've introduced a backordering system similar to many of the bigger registrars. The average expiry cycle is
two weeks awaiting renewal in the zone
two weeks awaiting renewal out of the zone
30 days redemption period out of the zone
7 days pending delete out of the zone
domain available for re-registering by a new owner.

The periods out of the zone will normally result in a page not found error whilst the domain is stil the legal property of the registrant. I'm thinking of replacing this with a warning page to the registrant so that the domain is not removed from the zone. I may add some links as the name will need to be renewed by me to save it from entering the registry redemption. I don't use j/script or redirects, so the warning page will be super clean.

What can I do to prevent the domain being blacklisted? Can something be added to the page for LL scripts to pick up, or should I make a list available to LL owners?