Dan, no, physical development doesn't "worry" me at all. If I had seen dichroic fog with my HC-110 monobath, I'd be concerned to find the correct antifog agent to prevent it, but there was no evidence of it. Further, this same solution has been used with a few different films -- Tri-X, where I tested it originally, and also Efke 25 that I'm aware of. Mine works well, I think, because HC-110 already has a strong antifoggant to combat dichroic fog, since it uses ammonia as part of the alkali (ammonia, I've read, commonly would produce this symptom of physical development).
In fact, monobaths were pretty common in the 1950s and 1960s, before Polaroid took over the "immediate results" market -- when a photojournalist needed to shoot, develop, and print in minimum time, especially in the field with limited or no ability to get to a formal darkroom, out came the coffee cup, monobath mix, and pencil. Use a rubber band to tie back the 35 mm leader (so it can't pull inside the cassette), drop the whole cassette into the coffee cup full of monobath, and agitate by rotating the cassette spool with the pencil's eraser. Wait a while (timing is non-critical, as long as it's long enough -- most worked in 6-10 minutes), pull the cassette out of the cup, pop the end, pull the film out, wash as much as you had time for, and slip the wet film strip into the enlarger (set up in the hotel bathroom, with a towel under the door). From camera to prints in under half an hour, better quality and bigger prints than Polaroid could manage in the day (which is why, until the Polaroid pos/neg materials came out, monobath still had a market).
And dichroic fog was never a major problem -- these soups were formulated to prevent it, by one means or another.