earlier I am a server manager too.. It's simply a plugin we can support admins through it. and those who ever camps will aware of their camp time. so what's your point? If it is classic then players can camp, at the same time admin should not slap or slay them. 
here i am talking about excessive camping. i know there is a limit player can camp. by adding this plugin we won't loose anything brah..
I personally think admins can tackle the issue of campers without the assistance of a plugin, especially on the Classic server. Server is fine as it is, admins do their job and make sure people don't camp too long next to/in base and actually complete the mission for each map. Yes it is classic, but do you want base campers to kill you with awps, knowing all they do every round is sit and hardscope with their snipers? I think there should be a challenge for the players, or the quality of the server will decrease and people will leave as the campers will ruin the experience, ending up the server being looked at as a "noob server". As mentioned before, classic is doing great, i don't see a lot of complaints about campers, only occasionally which means it is all going smoothly and the players are enjoying the server + admins are doing their jobs.
Also, yes you can change the amount of time a player has to camp until he or she will either get auto slapped or slayed, depending on plugin. But then again, it is not a major issue where we have a lot of campers on classic, normally everyone is pushing and trying to complete the objective, not sit around with an awp. Adding this plugin will just add restrictions to our playstyles, if you want it to be so "classic", there shouldn't be many/any unnecessary plugins, am i right?
I still do not support implementing this plugin into the classic server, but i will leave it up to high staff to make the final decision here.