I do not believe this suggestion deals with the issue at hand, which is that Custom Classes routinely in the past and possibly have continued to bypass SOP rules and restrictions for the branch that they paid to be a part of in their own custom class which is their particular "fantasy" or perhaps their preferred way to roleplay on the server. A better way to change this is through Rookieblue's suggestion which you can find earlier above. Increased communication to clearly establish the expectations and rules that a Custom Class must follow when participating in roleplay as a Security, MTF, CI, etc Custom Class to ensure that mishaps can be quickly dealt with while avoiding the excuse of "I didn't read the SOP so I didn't know" excuse or disregarding specific branches SOP's in favor of the less restrictive MOTD at times.
These Security Custom Class Owners specifically indicated they wanted their class to be considered Security. This entails following their SOP and MOTD rules in tandem which several posters above commented on examples of that not happening, which is why I talked about Rookieblue's suggestion as being more able to address the issue people raised in this thread. Changing their NLR timer does nothing but punish them for paying for a different experience than MTF, or CI which have to follow their branches SOP and MOTD rules with no distinction or special/detrimental treatment (I might be wrong about that, if I am then sorry).
This is getting long winded but tl;dr.
I don't think this suggestion addresses the issue with Security CC's and punishing them for not indicating MTF by treating them differently than other Gensec is not the solution. Please refer to Rookieblue's post if you need to clarify what I meant in most of this. Edit: If D class CC's had to pay an additional $50 then perhaps they should get the same nlr as normal d class.