Hello and welcome to the forum!
Jackson's need --and can only tolerate--about 1/2 the supplementation of Veiled and Panther chams. More is definitely not better when it comes to supplementing montane types of chams.
For that reason, I would be wary of using an all in one for use every day supplement.
Here is a thread with cautionary tales and they were not even Jackson's who had problems:
https://www.chameleonforums.com/repashy-calcium-plus-input-101541/
The typical forum recommendation for Jackson's is to use plain calcium at every other feeding. calcium with D3 1x a month and a multivitamin 1x a month.
The problem with RepCal Herptivite is that the vitamin A in it is beta carotene, a form that no one is certain that reptiles can actually use.
Zoo Med's Reptivite without D3 contains what is believed to be the type of vitamin A that reptiles can actually use.
Feeding the feeders a good diet (called gutloading) is an important part of a cham's nutrition. If the feeders are properly gutloaded then the multivitamin becomes a bit of insurance, rather than the main way of getting good nutrients into your cham.
Using a variety of feeders also helps to ensure good health.
Here is some basic montane species care. Jackson's are a montane cham, as you probably already know.
Fewer supplements, lower temperatures and more water are the most basic summary of how Jackson's differ.
https://www.chameleonforums.com/blogs/hoj/634-montane-chameleon-care-info.html
Hope this helps you.