There's no downside to raising on a note other than that any fundraising is time-consuming. It is becoming standard practice to raise money from angels on notes with caps adjusting upwards based on key points of the business proving more viable.

The worst mistake I see many accelerator companies make is that they don't fundraise enough to really stand-out at Demo Day or whatever the conclusion event is for your accelerator. The reality of it is that there is significant accelerator fatigue and most cohorts from even top accelerators are failing to find much investor interest/enthusiasm upon graduation. Companies must really be striving to be the *most* exciting (by way of traction or evidence of viability) by the time they graduate, so raising additional money now makes a lot of sense.