Before I begin, a recap and explanation:
Duelists's training allows a Makashi Duelist to add a single Boost die to lightsaber attacks while engaged with a single opponent, but also always adds a single Setback die to lightsaber attacks while engaged with multiple opponents.
The reason there is a problem with this is that it provides a disadvantage that always applies. I believe it is the only talent to do so. I also firmly believe that players should not be disadvantaged for buying a thing. This talent, as written, is terribly weak and has an awful negative.
I would quite literally take the long way around the tree rather than accidentally picking it up and penalizing my character for ever . I doubt I'm the only one who feels this way. This is a problem - there should never be a talent that a character would be worse for having.
I would like to suggest a possible new rule for Duelist's Training, but at the same time invite others to do the same. Let's get creative, find something that works well within the rules and the spirit of the Makashi form, and perhaps would even be something a player would like to have.
My suggestion:
DUELIST'S TRAINING
Activation: Active (Maneuver)
Ranked: No
Trees: Makashi Duelist
Force Talent. The character may take the Duelist's Training maneuver, commiting one Force Die. While the Force Die is commited to Duelist's Training, upgrade Lightsaber checks while engaged with a single opponent once, but add a Setback die to Lightsaber checks while engaged with multiple opponents.
I feel that this text gives significant benefit for a reasonable cost, and the disadvantage remains but 1) doesn't always apply, and 2) is weaker than the benefit gained.
I feel that this text is not perfect though. I see two potential problems:
1) Should it be a Force Talent and require a commited Force Die? The original was not a Force Talent, and so could not require a commited Force Die.
2) According to p. 196, a character can end an ongoing effect at the end of any subsequent turn as an incidental. Is this good enough to prevent the possibility of "on while it's beneficial, but trivially turned off so as to never suffer the penalty"? I tend to think so, since it would be a maneuver to turn it on again.
The other possibility that comes to mind is to have it be a maneuver to turn it on and off, and not require a Force Die commital. It seems to me that this would easily result in it only being active while useful and the penalty never applying. Therefore it would be the same as only having the benefit text, which I think is against the "feel" the designers are attempting to evoke with this power.