Here's the little rooted cutting I got on Etsy, looking pretty good i think.
It has ten mature leaves, and no new growth yet.
It came bare root wrapped in a bit of damp sphagnum. I potted it in an equal mix of orchid mix, perlite, and small bark chips. (a little sprinkle of bark on top to look pretty).

Its leaves really perked up after its first watering yesterday. Seems to like the bright SE window with a bit of dappled morning sun. After a day the leaves are beginning to turn towards the light and stand more upright.
I moved it for a moment to take its picture...

It looks great and I bet by the end of summer it will have doubled in size!

Thank you Lin. It will be very exciting to see the first new shoot appear, whenever that will be.
One question: The medium it's planted in drains fast, so do you think I should keep it moist all the time- because its root system is quite small and the roots are just little threads yet?
OR, should I already follow the practice as for an established plant and let the top of the soil dry out before rewatering? (I'm afraid to perhaps have the tiny roots get dry and die until they get more robust.) The root system seemed to have a few thin threads about an inch long or so.

The idea of the fast draining medium is to keep moisture from sitting against the roots. I bet if you dig your finger down in there, its will still be damp in a week.

I see what you are trying to say @DaisyI . I won't water it every day then. I'm glad this clipping has so many big leaves, as they help tell me when it's happy by the leaf greenness and perkiness. Thank you for your wisdom.

I love Hoyas that tell you when they need a drink. And Yay! that you are wise enough to "read" the leaves. Keep reading....

Your SE window should be great for it. In my experience, hoyas LOVE some sun -- I've got both of mine (a bella and a carnosa) in the sunniest windows I've got (south and west) and they are thriving! In fact, it's my understanding that many if not most hoyas truly need some direct sun indoors in order to have enough energy to bloom. (You've probably got a few years before it's mature enough for that, though, so don't get impatient!)

Thanks very much @romalu !

My pubicalyx Royal Hawaiian Purple has decided it is happy at home with me!
Over the past couple of weeks it pushed out a whole new stem from under the soil level. The new stem already has four baby leaves and a growing tip. I'm so excited!

And with summer approaching, I bet you will see even more new growth over the next four or five months!