They're gonna take 3 minutes to charge at tier 3 and have no tracking. I think you'll be fine.

With tier 10 discipline and mobility with double bomber mods, the cooldown will most likely be ~50 seconds. Bottom tree arc blade also decreases grenade/dodge cooldowns so grenade cooldown will probably be as low as 35 seconds. That sub tree also increases max sprint sprint so stompees can be swapped out to frostees so maybe even 25 second cooldowns after stacking everything. The lack of tracking really doesnt matter, plus there is going to be some aim assist.

You see the problem is when you speculate numbers you know nothing about. I would expect t10 discipline with flux to give a 70-90 second cooldown but I don't know that, so I'm not gonna speculate my opinion about it. A t10 handheld supernova is going to be a very big difference to a t10 flux grenade especially with the normalized contraverse hold.

Its an educated guess based off the current disipline/strength cooldown reductions (60% reduction of tier 3 = tier 10). But sure the flux cooldown could be similar to intellect and be ~135 seconds at tier 10 (25% reduction from tier 3). Then the cooldown will be ~60 seconds after stacking everything.