Ok....here is some quick info on my glass bowl experience and testing.
I have found that the straight side ones with the 8 pedal flower screen are the best if you are going to use a screen like I do. The ones with the single small exit holes can work and will add some extra pressure cooking to possibly work better with kief or bubble additives to your flower. But the problem I had was keeping the screen positioned without moving around too much when scrapping the left over abv particles and the screen would pop out or dislodge. Most of these bowls I found to not have a big enough flat area at the base to allow the screen to settle in and not move around so easy.
My first attempt using a glass bowl was with one I had from a water unit purchase.... It worked fair, but not at all good enough. Because it is a rounded inner wall and did not have enough flat space to keep the screen stable. But the problem was it has a tiny exit hole. So I new I needed something much much wider for free flowing convection. Picture below shows this bowl on the far right. (the one I use now is the one on the far left with a screen in it)
And here is the one I use now and the one with the small exit hole one. So that is the restriction you would be dealing with using a small hole one.
The straight sided ones like the pic below I did not like using at all and could not use them with my normal 3/4 inch screen bent into shape. They need a smaller screen and there is not enough flat area at the bottom to thus allow for a stable screen setting. Also they are what I call "pinch bowls", where as the actual load chamber is a double wall and not single. I did not like that for holding heat to keep the bowl warm enough to have quick draws constantly and more important, the double wall area did not allow heat penetration like a single wall. Though I do not think there is any conduction from this....
The one I use now from the bay
CAN BE FOUND HERE.......
OR ON DHGATE HERE
If you search around you can find many of these, but make sure to see a top view to show how thick it is. I saw some with logo's on them that did not seem to be as thick. Mine measure at about 4mm wall thickness.
Now comes the fun part....for me anyway. Adding the screen to the mix. I use a SS 3/4' screen and temper them with a torch. Then I form the screen to sit stable in the bowl. I use a nice high quality screw driver that just happens to have the perfect shape on the end to form the screen so it has a good flat spot that closely matches the size of the flat area in the base. It also is the correct size to bend the edges over to form the over all diameter.
And for a bonus............ if you have any of these bowls with some sort of handle or nub on it and they break off.....repair them with a simple paper clip for usage. I used 2 small needle nose pliers to wrap it around and bend a little handle.
I just bent and positioned a Ti screen from NV in this one....but I am thinking it may be too porous compared to the ones I get from a local shop. I will test this out this weekend and let you all know if there is any prob with the screen not being fine enough. I usually go with a medium to finer grind pending on moisture content and my level of patience ....haaaa