Yes, I think it’s better to think of low cadence work as good practice for climbing when under-geared rather than pseudo “weight training”.
*Coggan demonstrated that even at very low cadence (<50), pedal force is still far too low to represent a significant muscle overload. It would be like going to the gym and doing 1000+ reps. Coggan showed that “big gear” training is more like stair climbing or step-ups in terms of muscle force exerted. I think it’s fair to say he’s not a fan of the claims some coaches make about big-gear, low cadence training i.e building muscular strength, enhanced recruitment of fast-twitch muscle fibres etc. There appears to be a disconnect there between the science and cycle training culture.
Again, my own take on this is that it’s good to train within the cadence range that you will actually encounter on the road (for me that does include some sub 60 rpm climbing) and strive to improve your top-end cadence efficiency, which is why I really like the SUF cadence drills!
*re: Training and Racing with a PM