I forgot, what about beds or dispencers.
I just had some time (as the server is offline) to look for more
inventive ways of hiding stuff.
For me, most important is bed + gear.
Now, for a bed I've no problem putting it at 10k+.
Bad luck if it's found, but I check enough to make sure one is there.
(Can I have multiple bed's. or does only the last work?)
But for gear it would be nice to have places which can be closer to
spawn, at least with a reasonable chance to be overlooked.
Like hiding within ore or bedrock, but if it's outlined from great distance
that's useless. (They will not be perfect otherwise, but that's acceptable)
Alternatively I might consider placing many empty chest as decoy.
They're not that expensive.