Practically testing the waters is surely a good way to know of a casino is decent enough or not but sometimes, that can end up as expensive experiment if it happens to be an exit scam. Checking TOS and starting with little deposits can be a good way to start, however, learning from others who's used them of sticking to the reputable ones might just be the best to save yourself unnecessary stress because testing is also a gamble on its own.
One thing we should know is that we can not be too careful, even if we try all we can to be careful, the casino industry is such an industry that anything is possible, just as you have said, exit scams are unannounced and what if it happens when a player is trying to test the platform, although we can deposit a small amount if we want to do testing, but that won't save us from anything, it can only prevent us from losing much, you just nailed it, gambling with casinos that you know, is more adviceable, which is where I stand.
As you’ve already said, we can never be too careful, even casinos we know can also do exit scam despite the fact they’ve been in existence for some time, that could also be part of their plan. It is not also bad testing out new casino and that can be done with little amount of money as you’ve said to avoid regrets or losing a lot but in all, it is still good sticking to the ones we’ve developed some level of trust for and they are known for been reputable.