It all depends on what you mean under EJ. If it is switch to some equipment and playing it for a while it is one thing, if it is about trying something new each week than it is another. Also it depends on whether you work on your technique or you just play occasionally.
If you have your technique settled with certain equipment, then switching equipment will change something in ball trajectory and feeling in all situations which you already used to. So you will get worse in a short term. Then you will adjust a little bit and you will be able to hit properly while having to control some pieces of the stroke with your mind. But it is not really good for result in a match play, when your mind spends its resources on controlling angle, force or whatever is different to usual setup, instead of spending them on estimating incoming spin, speed and thinking about where to place a ball. It becomes noticeable for me at the later stages of tournaments, when mind is not fresh and probably lacks oxygen (especially in small halls in summer). And only then, after playing it for quite long period of time, you will stop controlling it in every shot and you can get better results in a tourmanent play (well, it is in assumption that original setup was suitable for you in general)
I've been playing with TBS for ~12 years, then tried TB Alc for ~2 years, SDC made blade with the same structure as Tb Alc for a year and then another Tb Alc again. All of them are with the same layers structure, playing similarly. But only after playing for about 6 month after each switch I was realizing that I don't think about blade reaction anymore, that I don't blame it in case of misses, that I can actually think in terms where I want to play instead of trying to control every aspect of my strokes. Rubber changes were easier in most cases for me, but still required quite long period of time to get used to and decide whether to stay with it or not.
But if your technique is still not really settled or you change your equipment quite often, and then work on your strokes. Then you can still progress with it. I doubt that it will be faster than if you use one setup that suits your game play/style, but why not. I have an example of a guy who was switching equipment in last 4-5 years quite often (blade and rubber, looks like he tried every off/off+ blade from butterfly and some from other manufacturers and every modern rubber from 5-6 manufacturers), at first almost every week, then giving maybe a month or two to certain blade/rubber combinations. And you know, he is definitely much better than he was 4 years ago and on a very good level for amateur player. I still believe that he could get even better if he settled with one setup 3 years ago. But EJ? EJ. Progress? Progress. I would even say, a very good progress for a person who has no coach and was not coached in a childhood. So yes, it is possible.