It doesn't work like that. Changes to show programming, require approvals and also require imaganeering to be there. Then there is testing, and sign off and such. A maintenance guy just can't go in and tweak a ****. Okay YES a maintenance guy COULD, but if that change is not in line with current show directive, then well someone's job is at risk.
That said, are there folks in the creative helm at Imagenering, who are supposed to do show quality checks.. and could push the issue, and coordinate with maintenance and arrange overnights etc. YES.. But will the paperwork needed trip them up, make it impossible and most likely not worth it.. well yes that to.
However, perhaps you could get entertainment to throw some money into the pot, by doing a temporary overlay (such as Haunted Mansion Holiday in DL) that tends to give a reason / excuse for those creative types and those maitnaince types to find some time to work on ahem.. little details.