Does en admettant que need the subjunctive?
Yes, en admettant que requires the subjunctive:
En admettant qu'il vienne...
Assuming he comes...
The Subjunctivator! | Quiz: Subjunctive or indicative?
Expressions with en
En admettant qu'il vienne...
Assuming he comes...
The Subjunctivator! | Quiz: Subjunctive or indicative?
Expressions with en
Source...