I'd probably start with a screwed-in insert of brass or steel in front of the mouth - since the plane will be on a shooting board, there shouldn't be much wear behind the mouth, and even if there is a little, it won't matter.
It doesn't seem like it should matter much in front, but it takes away your ability to adjust the iron depth by eye.
I'm sort of curious as to why some irons don't seem to take a fine edge. I never found Hock's O1 irons to be as good as the ones I've made on my own, and not as good as an O1 iron that I received from St. James Bay Tool Co in an infill kit (that one needed to be tempered).
If your iron fails to stop chipping after the following:
* several iterations of honing and use
* a total angle at the bevel of 32 degrees or so (you can treat it with a back bevel so that you don't lose clearance - 10 degrees is my personal rule, but you can go a little bit lower.
* accurate tempering to 400 degrees F
I'd perhaps try a different iron. There is the possibility of damage or decarb on the surface of an iron, but my heat treating conditions are far from ideal (coffee can forge, mapp torch, vegetable oil quench in a separate paint can, and then tempering in an oven to color on large irons - my oven is accurate, though - I have checked it with a separate thermometer.
Beach's page of irons shows the same thing I found with Hock's - that they are a bit more chippy than some others. I found Steve Knight's O1 irons to be absolutely wonderful (but they're not available in a shape that you'd like, and Steve is out of business), and Hock's larger custom efforts (one that I bought from Ron Brese and one that I bought directly from him) have also been good. It's the HCS stanley style irons that I've had trouble with.
I remember Ron Hock once saying that an O1 iron is ruined if you see any tempering colors, but I've found the range of 62 hardness tempering colors (straw) to be my favorite - the irons hold an edge well and are tough enough.
temperature schedules can be a bit inconsistent, but I'm guessing that the iron the plane in the video is somewhere around 62 or 63 hardness. It's too contrary to be sharpened on a washita.
Rambling on here a bit, because at one point, I believed harder was always better. Then I believed that 59 was probably more ideal, and now I'm sort of in the camp of trying for 62 hardness or so and if the iron works well, leave it alone. If it's too hard for my washita to remove material at a reasonable rate, then I just do the initial work with a fine india. I found the extremely hard untempered iron from st james bay tool to hold up to smoothing - surprisingly, and only tempered it later because it was such a pain to sharpen and grind.