"positively challenging" is correct and usable in written English.
You can use it to describe something that requires effort but is also enjoyable or rewarding. For example, "Teaching can be a positively challenging job."
However, it is also true that others perceive the speed to be adequate and positively challenging.
The Bailiff's role as presiding officer in the States Assembly has been "positively challenging" at times, according to Sir William Bailhache, who announced his retirement in 2019.
It's been a positively challenging experience that has been happening slowly over the course of the last few years.
The finding is in line with earlier interview study among Finnish GPs, where the comprehensive work in primary care was experienced as both stressful and positively challenging [ 44].
The BA seemed to be built on an inflexible culture and internal structure, too reliant on industrial sponsorship to positively challenge debate on the social implications of science.
Doctors (Table 1) felt positively challenged as role models, almost never felt disturbed and were positively motivated by a student's presence.
The physical therapists found the experience of working with the musician population rewarding and that it positively challenged their knowledge and clinical reasoning skills.
Apart from a negative experience due to increased stress levels, the transition period can also be interpreted positively as challenging, full of learning opportunities and opportunities for high performance [ 5].
Because growth forecasts become relatively so much more important to stock investors during bubbles, companies have their greatest incentive to spin news positively and challenge bad news during periods of stock market euphoria.
Its goal is to help you learn to think more positively and challenge negative thoughts and behaviors.
"In a decentralized place" like Time Warner, she wrote in a parting memo to her staff, it was challenging to positively influence hiring decisions from her corporate perch.
