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Resonant royer design for low noise, isolated DC/DC 1W

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In my search for low common mode noise isolated DC/DC modules I stumbled across a cheap Chinese one which gave spectacularly good results. Most likely it is a royer converter:
Fixed in/out, unregulated, cheap...

So I'd like to design my own. In contrast to the original Royer design, which uses core saturation to switch (and which is shown in the Recom page), I'd prefer a current-fed resonant one, as it is most likely lower noise and seems to have been standard in CCFL converters (See Jim Williams https://www.analog.com/media/en/technical-documentation/application-notes/AN118fb.pdf)
Royer converters seem to have gone out of fashion (at least the resonant ones with CCFLs going extinct, maybe with the exception of cheap B0505S DC/DC modules) and I could not find any hints on dimensioning.

Does anyone know how to properly design those? I am looking for a (what seems to be classic) current-fed resonant design as shown in AN118 figure 1.

Consider also ucc25800

Of course, that's on the list along with SN6507 and LT1533.
UCC25800 won't run from 5 V USB, which is something I'd need right now.

SN501/05/07  are trusty workhorses. Additionally, catalog transformers from W├╝rth are available.
You may also want to have a look at fully integrated transformers on-chip that TI offer. I forgot the GPN now.

Not sure what benefit a hard switching push-pull would give over buying just an off the shelf module.
I am looking for low noise, soft switching (possibly resonant).
So current-fed resonant royer would be on the list. UCC25800 also, although that won't run from 5 V and needs proper dimensioning of the LLC tank.
LT1533 probably would also work, but this is a hard to source (right now in stock), almost $15 part.
A royer converter on the other side might run with two $0.02 BJTs - that's what probably is inside countless cheap B0505S-1W modules.


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