I just did the same thing to remove a BB. Nothing else worked before I used the heat gun. This is only the second time taking out a BB and both times it nearly killed me to get the damn thing out. Cranks have been tough too, but not as much as these BBs. Is it normal for these to be so hard to get out? Is there any problem with applying heat, as long as you make sure the cables don't get damaged?
I completely coated the threads with anti-sieze when I put it back in. Bike is only about 2 years old, but it is used in almost all conditions.
I did buy a fixed 1-1/4" wrench for my BB tool, but the 10" adjustable I was using was of good quality (Craftsman Professional). I was going to try the little trick of holding the tool with a QR skewer but the BB spindle isn't hollow. Maybe the 12" adjustable I just bought would have got the job done without needing the heat. The fixed wrench is considerably longer than the 10" adjustable. The 12" adjustable and the fixed wrench are about the same length.