Apple has a choice to make. Will it make its Apple Pencil stylus compatible with devices other than its high-end iPad Pro tablets?

I think it should.

In 2015, when Apple first unveiled the Pencil, people wondered why the stylus wouldn’t work with non-Pro iPads, let alone iPhones.

Then, in 2016, when Apple announced the iPhone 7 and 7 Plus, people wondered why Apple didn’t make the phone capable of supporting the Pencil.

Now Apple is said to be planning its third iPad Pro. It’s reasonable to expect Pencil support on the new 10.5-inch iPad Pro. But will Apple make an oh-by-the-way announcement about expanded support for Pencil after revealing the new slab? Unlikely.

If anything, Apple could finally bring the Pencil outside iPad Pro land in September at its next iPhone event. Will it? I guess so. There will likely be new OLED displays on Apple’s 10th-anniversary iPhone. At the same time as it refreshes the displays, Apple could also introduce technology that can handle the Apple Pencil’s sensors for detecting pressure, angle, and location.

Apple’s closest competitor in the smartphone market is Samsung, whose Galaxy Note phones have for years shipped with a stylus and a nifty, narrow on-board pocket to hold it. Earlier this year, Samsung introduced convertible Android-friendly Chromebooks with that feature, too.

Must Apple follow Samsung in bringing stylus smarts to its flagship phone? No. Should it?

Well, look at iPad sales. In the holiday quarter, the most important quarter in Cupertino, iPad revenue was down 22 percent year over year, and iPad unit sales were down 19 percent. Revenue growth for the iPad has been erased — the single biggest quarter for the iPad, revenue-wise, was back in 2013. The iPhone, meanwhile, is back to growth, with record revenue and unit sales.

In 2012, Apple did bring its Siri virtual assistant to the iPad — the company’s newest device at the time — after debuting it on the iPhone in 2011.

Now, after Apple has granted the iPad Pro more than a year of Pencil exclusivity, it would be wise for Apple to start letting consumers decide if they’d like to buy a Pencil for their iPhones — while the Pencil is still interesting.