In reply to Si dH:
Thanks Si dH, I had previously experimented with repeaters but found the holds simply too big to be working anaerobic endurance within the forearms; as you mentioned yourself. I did also experiment with adding weight to it to make it work but found I was having to add a stupid amount of weight and decided it wasn't sensible. But I did not think about adding cardboard cut outs to reduce the hold size, that sounds like a good idea, will give that a shot - thanks.
It is interesting what you say about being 'powered out, not pumped', I have been wondering about the distinction between this myself. As I have been finding on sport routes around the 7a to 7a+ range that across the 14-16 move range (circa 90 seconds of continuously sequency climbing) I will power out, not pump out. What is the difference between the two sensations? If I am climbing indoors at Ratho I will get pumped out my mind as desired quite easily around 20m up on steep 6c+/7a routes. Is the difference purely that 90 seconds of sequency climbing is slightly more strength related on the spectrum of anaerobic endurance, meanwhile being pumped stupid is more so endurance based on the scale, i.e. takes more than 90 seconds?
As you also discussed further down, doing Frenchies with pull ups on the jugs was a good exercise for the shoulders and upper arms, but I didn't feel too much work directly in the forearms.