There will be a difference if the performance is dropping because the hydrophobic effect of the coating is actually wearing, or dropping because it's become clogged with contamination or an abundance of toppers. If the coating is wearing, then no amount of decon is going to work, and can possibly make things even worse off on a fragile coating if the decon is heavy enough. Certain toppers may be a good option to even things out with a satisfying experience during the follow up washes until you fully remove the coating and start fresh.
I still like the philosophy of lighter toppers to maintain a healthy coating, because in my case I will build up hard water contamination fast enough to where the paint just doesn't feel silky or smooth after drying, well beyond the already not-as-slick effect most silica-based coatings offer from the start. And hopefully the topper is compatible enough to not have a large impact on what I like to see out of it during follow-up washes, while getting rid of that grabbiness after drying. Or if I'm washing outside or have no garage access, I'll always get some sort of drip lines that I want to clean up with something.
My other option would have been to go with a dedicated waterspot remover, however I've seen some fresh coatings be destroyed or impacted by them, Skin EVO on top of two coats of Mohs EVO being the latest I've tested that did not respond well to Gyeon WaterSpot, Mohs EVO by itself held up perfectly. No amount of decon washes or follow-ups was able to get Skin back to its performance prior to using WaterSpot. My only option would be to top it up with whatever.
This leads us into which types of toppers to use, and this is possibly paint dependent. Sandro's use of Bead Maker on top of CQuartz coatings showed a decrease as shown in the video above, whereas Bead Maker on top of my CQUK 3.0 and CQuartz TiO2 on the test 2010 Honda was absolutely perfect, it maintained the hydrophobics extremely well on CQUK and even boosted TiO2 to better than what I was seeing when it was bare and fresh and months since the last Bead Maker application. So CQUK/TiO2 curing into this sticky type of Honda paint could potentially respond better, last longer, and be more compatible with a greater range of toppers compared to it curing on top of different paint, just a hypothesis.
Bead Maker responded well to every single coating that I applied to that Honda, up until the point to where the coatings were degraded enough to where they needed a more hydrophobic topper or proper decon to be able to maintain high performance during the next washes. This is why I was a big advocate for it, although if you put Bead Maker on top of something like the insanely hydrophobic Zymol waxes, you will immediately reduce their hydrophobic effect and you'll never get that back (which may be fine because their peak performance by themselves does not last long in the real world anyways).
Heavier toppers I've not been a fan of early, except for Polish Angel. Trying to top CQUK with something heavy like Turtle Wax Seal N Shine, Flex Wax or something like Griot's Ceramic 3-in-1 Wax is going to overwhelm the coating with that topper, and you're almost guaranteed to reduce hydrophobic effect. I would assume if CQUK had any sort of advantage in self-cleaning or dirty shedding and then you go and put those on top, you're going to get whatever they offer until CQUK sheds them off the paint, which I can guarantee you is not as good as fresh and healthy CQUK. Same with Brilliant Shine Detailer, it'll take longer to shed off the coating which is fine if the coating is already worn out, but just not necessary if the coating is healthy if my only goal is to maintain some sort of slickness. Polish Angel is hydrophobic enough to where it seems like it plays well with the coatings, and I didn't get the impression that they were clogging them compared to Seal N Shine and Griot's.
With heavier top coats like Skin EVO, Can Coat, Gliss, EXO, I wouldn't hesitate as much to use them because by themselves they are great performers (aside from Skin EVO since it hasn't been out long enough to confirm). But same story, you put Skin EVO over two coats of Mohs EVO and you're getting Skin's performance. Which means less oleophobic, less chemical resistance against acid-based waterspot removers, but overall more hydrophobic.
I would recommend periodic decon washes and steps down the road to maintain the coating, regardless if you're topping regularly or not. But if you're planning on using toppers, I would guess that it may take some experimenting to find the topper that is going to provide you what you want to see, which may differ from someone else using the same coatings and toppers on different cars and paints. For me, letting the coating run its course bare without anything is not an option.