I've had 2 vehicles in the (way) past that developed injector issues, 1984 Turbocharged Buick Regal T-type (bought new), and a 1984 turbocharged Chrysler LeBaron (bought used)-- both cars got to a point they wouldn't pass an emissions test--the T-type had its injectors pulled and installed in the shop's injector cleaner on Friday before they went home for the weekend, where pure acetone was forced thru them the entire weekend. About 10am that next Monday I got a call, telling me 4 injectors are 'working better', but 2 needed to be replaced. DID make a big difference--
The LeBaron, which wouldn't pass an emissions test due to the O2 sensor not being able to compensate for the dirty injectors, the (different) shop suggested a rail-flush, no injector removal necessary... And they did run the car while they did the flush, about 3 minutes of pure white clouds of smoke from the exhaust. I had a ride home so I didn't get to see the whole procedure, but when done it passed emissions with flying colors and ran fantastic...
HOWEVER, back in those days, I was told by mechanics that Chevron gas was causing injector issues, problem with their Techron or something...
Anyway, I can say that both procedures worked. And I can also say, that since I've never had another injector cleaned in my life since the Ttype and LeBaron, including the injectors in my 2002 Ford F-250 I bought new and still own. Still runs like new-- of course, it just barely hit 64,000 miles last month, but that issue could lean either way; low miles means low usage, but low usage sometimes leads to gummy deposits building up.
So I would say, 'if it ain't broke, don't fix it'... And I did learn a way, with the LeBaron, to tell if injectors are dirty: When the mechanic did the emissions test on the LeBaron, he showed me how he knew the injectors, in his opinion, needed cleaning: He was holding a gauge that was reading the 02 sensor's voltage, and while idling, the needle would slowly but noticeably swing back and forth slightly over the course of about 5 seconds- he explained that the sensor and ECM were constantly trying to adjust the fuel delivery to keep the 02 levels constant, and couldn't because one or more injectors either couldn't keep up with the needed flow, and/or injectors can get to a point the put out a 'pee stream' rather than a fine spray... a pee stream of fuel won't atomize as it should...
Or just get an emissions test, if your car passes, your injectors are likely fine...