Taking this story at its highest, it strikes me that this offence would be very hard to prove. You would need to show, beyond all reasonable doubt, that the offender knew the person was transgender, that they were motivated by hatred of transgender people, not a mere dislike of an individual, or an accidental mistake. An aggravated offence as opposed to an aggravated sentence is very hard to prove and charge.
Technically, it may excite a few posters to know that the reason there are not more aggravated offenses is that the charging standard is very high in terms of the evidence required, and the prosecution is very likely to fail.
This is why, many years ago, criminal justice policy was set to aggravate the sentence, not the offence, because you die not have to have a separate hearing on the evidence regarding whether the offence was aggravated itself because a defendant could admit the basic offence but not the aggravating element (ie I did hit him your honor but I am not a racist).
The costs of longer trials and a separate criminal process was significant.
Therefore, you aggravated the sentence because a judge could do that based on the findings of fact for the offence.
There are a lot of technical legal issues beyond that, but even if this proposal were real, it would be costly, ineffective and nearly impossible to prove.