when you use Juniper Supplicants like Pulse or OAC for both L2 & L3 connection on same computer only one license is consumed
When you use only windows supplicant for 802.1x for Layer 2 connection and pulse for Layer 3 connection UAC will use 2 licenses for this.
This is applicable for MAC or LDAP or AD auth server. Hope this resolves your query on concurrent licenses.
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