This entire case if (unfortunately) pretty similar to Request for Elastic Security Free Trial Extension for SOC PoC Internship Project
There's no great solution to this right now but let me see if we can figure something out.
In the meantime, figuring out an automated way to recreate the environment with a new trial is probably the safest bet.
PS: If you do a full snapshot restore with the cluster metadata, you are IMO not able to do another trial (on the same major version). Haven't tested it in a while but I think that trial state is kept in the metadata.