Ofcourse!
With the injectors it’s all dependent on the load applied to them. Low load low stress. Makes sense right? Once load is applied small defects can show. They can be intermittent or permanent.
But you’ll need to get some data out of the car. Cause it can be a broken diff or a simple speed sensor not working.
With the smooth running test you check for internal load balance. There you can see if an injector is dead or dying.
Physically you could also check the dreaded injector loom. The tend to fail over time. New one isn’t that expensive. I changed mine and it felt like I got 50 extra hp.

Well with that experience you can also maybe help me out in the future. Currently purchasing a HET and closed a contract on 15 snatch land rovers.

Hope the info helps a bit to get to a starting point