QUESTION:
Is it possible to increase the limit beyond 40 total rules across all scenarios of a particular type?
ANSWER:
Yes. There is a workaround to the scenario rule limit but, the downside is the possibility of running into exceptions by going over apex limits, so implementing this is "at your own risk".
A setting can be added to the DupeBlocker General Settings table (DupeBlocker 3) or the DupeBlocker Settings table (DupeBlocker 2) with a name and index of "Disable_Rule_Limits" and a value of "true". This will provide the ability to bypass the scenario rule limit, but also introduces a risk of causing exceptions by going over apex limits.
If you are willing to risk that, then the easiest way to add this setting is to open the Developer Console window (click on your name in the upper right and select Developer Console from the drop down). Select Debug -> Open Execute Anonymous Window, paste this code into the window and click the execute button:
DupeBlocker 3:
insert new CRMfusionDBR101__General_Setting__c( name = 'Disable_Rule_Limits', CRMfusionDBR101__Type__c = 'boolean', CRMfusionDBR101__Boolean_Value__c = true );
DupeBlocker 2:
insert new CRMfusionDBR101__Setting__c( name = 'Disable_Rule_Limits', CRMfusionDBR101__Index__c = 'Disable_Rule_Limits', CRMfusionDBR101__Value__c = 'true' );
More information on the Scenario Rule Limit in general can be found here.