Not sure why the confusion. Since EX2300 VC (whether -C there or not) requires a license per switch, you would purchase the EX-12-EFL for EX2300-C and EX-24-EFL for EX2300, no? Separate different license per model. For EX2300 every switch in VC requires a license. You can also purchase EX2300 model SKU that includes EFL for VC.
Juniper price list shows (EFL coverage for 2200 is NOT the same as for EX2300):
| EX-24-EFL |
| EFL FOR 24 PORT EX2200, EX2300, EX3300, |
| EX-12-EFL |
| EFL FOR 12 PORT EX2200-C AND EX2300-C |