I am but an enthusiastic amateur. I do have the good fortune to have a few friends who are not only incredibly talented, but quite happy for me to hang around and learn off… …I also have friends who don’t know the difference between a a spanner and a screwdriver..

What I have picked up over time is by a fair quantity of personal experience….which is then usually corrected by or added to by others.
The consensus is that inners wear quicker. Oddly, my first experience was contra this. Anyway replacement shoes are of far better quality than the originals.
Now, folks will tell you that “upgrading” to hydraulic tensioners or even gear drive is the way forward. Sure, if you’ve got the money and inclination. Replacing the old tensioners with later ones and keeping an eye on them is just fine, if you’re happy with the motor as it is.
Now, I wouldn’t normally suggest this, but have you considered joining a local group? There will be a wealth of local knowledge (as well as lots of opinions) and advice to who’s good with spanners in your area.