If you have a huge number of websites to block and that list is common for all the webfilter profiles (if you have too many) , then it is good to go for "custom category" where ,you can put all the urls in the custom category and block that category in all the profile.
In this scenario url filter is not advisable because, you need to go to each webfilter profile and add the huge number of blocked website entries every time.
If you have a less number of blocked websites and list is different for all the webfilter profiles, it is advisable to go for url filter.
Similarly, you can configure other urls or bulk urls for your configuration and then copy & paste the same urls configured on one web filter profile to different webfilter profile through the following cli commands.
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