Correct. They'd have to do a run of 500 and charge the equivalent of what Craft and the MoFi One Steps go for, but with more LPs (so around $300 I'm guessing for this Henderson set).
The retentiveness of the customers in that market is off the charts, so anything less than perfect would be sent back. So they would have to invest in some very high level QC. But...they'd sell out preorder if they did this. Blue Note knows this market for jazz vinyl otherwise they'd never do that Lee Morgan Lighthouse complete set. They have more scale of course than a small player like Mosaic, but I'd have to think those guys can pull some strings, call in some favors, etc. to get it done.
All of these small labels press limited run LPs on Bandcamp and for the more well known artists, they sell out in presale (See what Hive Mind did for Sonny Sharrock and what's probably about to happen with Sun Ra's Lanquidity). It can be done, but I have no doubt that Mosaic's heart isn't in that type of product anymore.