Short answer is nothing more you can do other than get a command system
1. I assume when you say “chuff” you mean you never see individual pulses of smoke. Answer to that is most likely in a conventional environment you can’t go slow enough where you see that and still have enough voltage to even make smoke
2. It’s not impossible that the batting needs to be replaced for the whistle but again in conventional unless your running it at full voltage your not going to get a full amount of smoke. I’d put it in neutral and crank the voltage to 18V let it set then lay on the whistle if there’s no change then I’d start looking at batting.
3. Blowdown is ONLY available in a command environment
