The issue of helmets with cameras interfering with the deployment sequence is well-trodden, to include on dropzone.com.
In France, new safety regulations produced by the Federation Française de Parachutisme, the sole, recognized sports authority for leisure skydiving, have become extremely stringent regarding camera mounts, and in particular, the way they protrude.
So a French skydiver, Olivier Hiolle, developed a helmet specifically integrating the most current cameras of the day, i.e., GoPro 3 and 4 series.
The result is astounding. The GoPro is fully inside the helmet, which has a frontal window.
The top of the helmet is flat in order to accommodate other cameras. Of course, that would be a departure from the initial idea of having no protuberance, but there is no other way to carry larger devices.
The helmet itself is a "true" helmet, in the sense that it is made of strong, resilient fabric and serious cushioning that will effectively protect the head in case of shock. We are well beyond the degree of protection afforded by basic helmets, in moulded plastic, whose protective function does not go much further than just providing a convenient attachment for a camera.
I have ordered one and flown with it a dozen times. The fit is extremely comfortable and natural. I have a GoPro 3+. I purchased, as an extra, a USB cable that remains coiled inside the helmet. That way, I never manipulate the GoPro directly, apart from activating the bluetooth by slipping my little finger into the lodgment of the camera. From then on, I use the remote control. When I wish to download the pictures or load the battery, I just pull the cable out of its lodgment and plug it where it needs to go.
The angle is perfect, no vibration whatsoever, and good sound under canopy (in the sense that I can hear myself grumbling and commenting on the approach).
This is a new one-man firm, who makes each helmet by hand, to include the color. Prices are reasonable, including options such as color (other than white or grey for the fiberglass version), cable, chin strap. By design, the strap, whether chin or basic, has a quick release handle.
This is the website: http://www.skyvisionpara.com/index.html, which, at present, is only in French.
Be aware that the photos I lifted from the webpage are not as good as the current product. It is a much more polished work than that. But the photos do give an idea of the design.