Power feeding means that you are feeding an increased amount of proteins and fats to get quick growth, bypassing the other portion of the diet which offer more of a balance of vitamins and minerals. The problem when people power feed varies on the species. With chahouas it can lead to MBD, calcium crashing, and vitamin deficiencies. The thing about chahouas as say compared to cresteds, they require more protein anyways. Power feeding is normally done to try and grow up faster to breed, chahouas actually grow rather quickly when fed correctly, the problem with them is egg laying takes a lot of them which is why it is recommended to wait until they are older instead of going by weight. The idea of power feeding comes more from the crested community which more people focus on weight rather than age so they will try and bulk them up quickly to 45g so they are considered breedable.
@MelissaSR hit it on the head by saying that at least with chahoua, it's a little more contextual than with other New Caledonian species.
Years ago, many people kept Chahoua the exact same as they kept cresteds: lots of fruit, few insects. That diet regimen is OK for cresteds, auriculatus, and leachianus, but less so chahoua. What could be considered power feeding for one of those species is probably a great diet for a chahoua, in my opinion.
I feed insects 2-3 days a week, and fruit diet another 2 days a week. My geckos eat LOTS of insects and when fed as such, juvenile chahoua can grow very quickly. This bug-heavy diet is definitely better for chahoua though, IMO.
I think you see the term ‘ power feeding ‘ used more in the context of snakes that will eat any and everything you offer and get obese. Sometimes gecko people may offer pinky mice and fatty wax worms as additional calories. Both are high in fat. Years back I would offer new born frozen / thawed mice to chahoua. Some are afraid of it , some grab and spit out later. I may have had a couple chahoua actually eat it. I don’t bother offering any more , but years ago it was only couple times a year. I know of no way to make a chahoua eat any more than it wants to.....