Re: My Hunker. It is a waterproof zip and the lady who altered it for me also sewed and sealed a 2" strip along its length to cover the zip, just in case the waterproof zip isn't waterproof. Once done it made such a difference to an already good bit of kit. I also had a Stratosphere Bivvy with a hooped hood, I just could get on with it, I prefer (unless it's raining) for my head to be exposed to the open air. The Alpkit 3.5 is also an excellent item and it compliments my Hunker very well.
As regards one-man tents, I've had a Marmot Pulsar One for a number of years, its a bit careworn now and I have looked for a replacement but just cannot find one that matches it. I can get a lower weight of course and I can get a better colour (mine is orange) but in terms of internal space, almost vertical walls, a 12" length of sit up straight area and a 12" zipped area to leave things outside (like my Uriwell) on the non-door side, so have never found one. Sorry, not quite right, there seems to be a similar one on the Naturehike site but that tent is heavier than mine. I think the nearest I can get to my criteria list is an MSR model but it has less internal room. I'll keep looking but because of Covid-19, I'll wait until spring before I finally decide.