I've been working out for... 11 years? No seriously for 11 or 12, not seriously since high school.
Many of the exercises I do involve locked symmetry between two arms. Things like push ups and pull ups, you presume that the arms will train equally, and it feels that way, however, some exercises like anything with a fixed bar on tracks or even with the rope in triceps work, asymmetry can result.
Mostly because I maxed out one machine I have been doing that exercise with one arm and the left and right are different, so I switched everything over to independent arm work and most exercises are symmetric but I have noticed that my right has more strength by 10% but in some cases less endurance. I kinda knew that but now it's been quantified. I can't see ot or measure it on my body but when I'm doing 90% 6x6 and then work to exhaustion which I didn't ever do before intentionally, surely my right is stronger but has slightly less endurance in certain exercises. That will obviously adjust as I continue this style of exercise.
Free weights over bars, wire machine with independent weights for each hand, and things like bench and even rope, independent hands is the new way.
I'm always mixing this up because I get bored easily, and it's certainly fun if I see gains week to week.
As far as gains go, i can easily see 10-25% gains for exercises I've never done before, even if they are muscle groups I am used to, this has to be mental, but even those exercises I do regularly, this 6x6 followed by lift to exhaustion is making 10% week over week gains, that's crazy.
Having my arms sore for days, that's crazy.
My legs sore for a week? That's crazy.
Go for it, but again if you're sore, don't exercise that group again until it's no longer sore. If you have joint pain or tendon soreness, you have to let that heal. Tendinitis takes a month to resolve, let it heal.
Good gains to all.