I top up with Orange seal every couple of months. I’m using GP5000TLs and since they have a inner butyl layer the tire is not porous at all and the sealant lasts quite a while. If you have tires that weep from the sidewalls then your sealant won’t last as long and you’ll need to top up more frequently.
I just changed my rear GP5000TL after a year of use and many top ups with orange seal. It had maybe a 10 gram snot ball of latex in there and some liquid. That ball was nothing.
I learned from my gravel tires that it’s never worth it to take the tires off and clean them out. Just keep adding sealant as needed and then toss the tires when they are used up. There’s nothing more to do.
That said, get yourself a good syringe and valve core removal tool. Always take the core out and clean it when topping up sealant.
If you get the kind of syringe with a skinny tip then you can stick it down inside your valve and try and remove whatever sealant is still there letting you know how much as evaporated. I did this once and then realized it wasn’t a crucial step. I just keep topping up. I’d rather have extra sealant then not enough. I could care less about an extra 10 or 20 grams of weight.