Is anyone using a matte box, either with a 35 mm adapter or exclusive of the adapter, with their HV 20?

I'd like to add one to the kit but have no immediate plans for a 35 mm adapter. Most of the matte boxes I found by searching are part of adapter kits or looked outright flimsy with no provision to add filters.

Thanks
Bob

Yes, I was on a set where one was used with a 35mm adapter and matte box from Cinevate. (www.cinevate.com) There were carbon fibre rails as well, so, the mattebox and the HV20 alone could have been used together without the 35mm adapter needed.