These 3 shortcuts loop through the same 500 items, but on my iPad:
➀ Repeat in [array] takes 0.6s
➁ Repeat in [dictionary → array] takes 8.2s
➂ Repeat in [text as dictionary → array] takes 21.8s
For best performance, execute type coercion or dictionary value extraction before repeat.
https://www.icloud.com/shortcuts/ec85db3df8f04df79cd3a88c26fa044e