Really do not understand "Your" question . . .
What is "Vape through" ? ? ?
Do - "You" mean using the Cool Fire 4 to vape while it is charging - which is more commonly known as "Pass-through" . . .
If so - well after doing a little research on the internet and ECF with just the words "Cool Fire" & "Pass through" I found that . . . Yes - "You" can use a Cool Fire 4 as a "Pass-through" with no ill effect on the battery (although it may get a little warm - so be careful) given the technology that
@innokin has incorporated into the Cool Fire 4 . . . SO "You" would be Good to go . . .
Hope this was helpful, but if Ya' want to make sure - Someone else will probably also provide an answer too . . .