There is no right or wrong answer, but FYI, my last two pairs of floor standing Magico speakers shipped in separate palletized crates in the upright position, with my current S5 Mk2’s shipping with castor feet for easy unloading, however Magico use a suspension system and ingenious locking system to secure the speaker in the crate...and Magico’s floorstanders are built like a brick outhouse, so they can handle it.
My Marten Coltrane Alto’s (large stand mounts) were shipped in their 3 factory cardboard boxes in large foam mouldings for protection packed in one palletized crate by the seller, with the main speaker modules facing up.
I know classic Infinity speakers like the Rennaisance 90 & IRS Sigma shipped in factory cardboard boxes in foam mouldings in the upright position fyi. Though the pair of 2nd hand Ren 90’s I bought were shipped o/s in a single crate with the speakers wrapped in heavy bubble wrap & foam, again in the upright position.
However I’ve successfully shipped a pair of Magico S5 speakers (190lb) interstate in custom palletized double-boxed cardboard cartons with the speakers lying flat on custom injection-moulded foam wrapped in bulbble-wrap with the drivers facing up. The main challenge was to ensure the top and bottom foam mouldings had clearance around the drivers & speaker binding posts. That done, The speakers arrived with the buyer in micky mouse condition due to of the extreme care taken to pack & ship them.
I’ve also bought a pair of Evolution Acoustics stand-mounts which shipped in low, flat crates with the speaker modules lying on their sides. Hope that helps!