Short Answer: I do not think he had an option to treat Luke the same way. At least not immediately. Long term? Well, that is another mater entirely.
The Mind Transfer rules and limitations
"You want to kill me. That is what I want. Kill me, and my spirit will pass into you. And all the Sith that live in me."
Darth Sidious to Rey, The Rise of Skywalker
In essence, the force is a magic system. And it is a exceedingly common rule that permanent mind transfer or power inheritance works better/easier/"only" with Blood relations:
- In Dragon Age, Flemeth was seemingly limited to transfer her mind into biological daughters of her current host
- In Batman Beyond "Out of the Past" there was similar story (besides using Computers): Rhas was at first only able to only transfer his mind to a "close genetic match"
- In Marvels X-Men movie "Days of Future Past", they are only able to send back Wolverine into himself
- In Assasins Creed a thing that is - in effect - time travel, is explained with "Genetic Memory" and a VR simulation. A Blood requirement with another limitation
- Propably a few dozen other cases that I can not remember of the top of my head
It think it is save to infer a similar limit to this little thing.
However, note that the Batman Beyond case was a bit if a subversion: Originally only a close genetic match would work. But he had been working on it until he was capable of transfering himself into
a lazarus pit rejuvenated Bruce Wayne.
So short term Palpatine would propably have no option.
Long term? I would bet a Death Star worth of credits it was a longterm plan. It would have propably been a lot more work - requiring both reinforcing the 2nd Skywalkers Dark Side connection and a more elaborate ritual setup - but it was not off the table.
The whole Family thing ran in paralell of course. Palpatine was always one to hedge his bets. And why do the hard thing, if there is a low hanging fruit you just need to pluck from the family tree?
I can feel your anger
"Good. I can feel your anger. I am defenceless. Take your weapon. Strike me down with all of your hatred, and your journey towards the Dark Side will be complete."
Darth Sidious to Luke, Return of the Jedi
I think his short term goal was to either:
- turn Luke or Leia to the Dark Side, to get a younger and less damaged model of Skywalker as his hand. Despite his performance, Vader was hindered heavily by being mostly cyborg/dead. I think the novellisation of "Revenge of the Sith" spelled that out.
- have Vader kill Luke and Leia trying to convert them, to remove the remaining goodness that might have turned him back or hindered him from unlocking his full potential
Both would have served him as well as the defeat of the rebellion.