Denali mini could be a tight fit on full left lock - will be interested in how you get on as it is on my wanted list. I managed the fenda extender with mudguard in situ. but I had the pyramid version which could be stuck on before I used the rivets.
Just checked, seems it might be a tightish fit but should be okay. The Denali mini is wide in diameter but not massively thick at the top, where it will be closest to the fork. They supply also a new mounting double plate metal thingy, which I think is slightly longer than the oem one so should bring the horn a bit lower. I'll try installing tonight if I have time and will update.
The R&G fenda extender also has the sticky tape, but I'll remove the fender anyway to see how it works and do a clean install. I want to put some sikaflex ebt on the inside joint too so it will stop dirty water leaking through the tape over the fenda extender and will also dampen any vibration.
Denali supply a purpose made bracket for the AT to mount the Soundbomb on theLH side of the engine. It works well and is fairly unobtrusive.
Just to clarify:
If you mean left hand side on the actual side of the bike then I think you mean the bracket for the full Denali Soundbomb 120db version?. That looks good and is probably ridiculously loud but was more expensive and requires additional wiring, not plug and play.
If you mean the left hand side of the radiator at the front, then yes, the 2 layer metal bracket supplied should be a bit longer to increase clearance.