I don't believe that this LEF provision would have any bearing on performance of the QV environment. Suggest that you ensure the QVS Events log are configured for High verbosity and review them for errors/warnings.
I was able to find the following from some internal documentation on LEF file contents:
A limit on number of CPUs. The has not been used since version 10. Last time used was in version 10 of both the Desktop and the Server. This attribute was also removed from any new license key as of November 2014.
You can check with your Qlik account manager about this LEF provision if you have more questions. Hope this helps.
Sr. Technical Support Engineer with Qlik Support
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