My exp with elear was prob the same as you.The hiss on AMP9 never bothers me but using any amp module DX220's not good on full can.
Even with the low impedance D9200 it didn't sound too good. I find DX220 to be a portable
dap having good synergy with most of IEMs, not with hard to drive HP. Even the pico amp
couldn't revive the sound but may be WA11, yes.
I was always convinced that elear will be less driven by AMP8EX-FE,
So by pairing to ifi Zen Dac or NX4DSD, will be OK for my taste...
then I did trial for synergy, by changing my cable (Brise) from mmcx to 3.5SE... and Mod my DX220 Body to similar like EX...
the result, I might say DX220 Mod + AMP8EX-FE + Brise > Elear, was great, enough power to drive. and comparable to external Amp pairing...
And this is based on my exp...
my point, explore it ur self...