Modern EL34s VS NOS Winged C - and return policies?

A couple questions for the tube veterans here:

1. If I buy a new set of premium tubes and they sound fine but just don’t have the magic I’m after, can I usually return them?

2. What current-production EL34 comes closest to the NOS Svetlana SED Winged C?

My setup:

• Sonore ultraRendu streamer

• Gustard R26 DAC

• PrimaLuna EVO 400 preamp

• PrimaLuna EVO 300 power amp

• PureAudioProject Trio15 Classics

I’ve rolled Tung-Sol KT150s, KT120s, Gold Lion KT88s, the stock PrimaLuna tubes, and NOS Svetlana SED Winged C EL34s. The SEDs absolutely destroy the others in soundstage and holography — it’s not subtle. I often struggle to hear big differences between DACs and streamers, but the SEDs are jaw-dropping.

I’m tempted to sell off all my other tubes and double down on EL34s, but I worry a new set might not have the same magic. I’m also willing to pay for another set that does.

Any thoughts on modern EL34 alternatives or experiences dealing with tube dealers who are sympathetic to nutcases like me? Thanks!