Lot people seems misunderstanding about
"Can play it with decent volume and still have plenty of space"
And
"Drive properly"
Planars need good amplification. All sources can play planar, with decent volume, but planars are hard to drive properly. When planars aren't driven properly they sounded different, flatter, not as dynamic.
IEMs usually scale better with better sources, but from experience, planars have quite big differences if not properly driven.
I have popular apple dongle, the timeless when connected to it, i still have plenty of volume space, but when connected to DX160, they are on another league, quite a jump and when connected to M11 plus ESS they are better (though the differences not as big as from apple dongle to DX160)
Same with TWS hook. Connected to TRN BT30 timeless sounded very bad, no dynamics. They become lifeless instead of timeless. But when connected to Fiio UTWS5 they can be driven quite decent even not on DX160 level, let alone M11 plus ESS.
My Z1R on other side is easier to drive even with only apple dongle or KA3 (dongle) though they scale better with better sources.