AFAIK we have no official spelling for B'Elanna, though I generally use *{be'elanna} for the reasons you stated.  Ditto for Gorkon though, not knowing it had appeared in Hamlet, I’ve used *{ghorqan} which reflects how it’s pronounced by human actors.

--Voragh

From: De'vID
Sent: Tuesday, March 27, 2018 5:33 AM

The Duolingo course uses the names of existing Klingon characters from the series, and it spells their names in Klingon.

There were two names which I'm not aware of having appeared in Klingon canon, {beylana} (B'Elanna) and {ghorqon} (Gorkon). 

I'd have expected *{be'elanna}, based on the prior example of {be'etor}. The KlingonWIki *claims* that {beylana} is used "in email list", but I couldn't locate any uses of it. Has a Klingon spelling of B'Elanna appeared in any canonical or even extended canonical (Star Trek canon but not tlhIngan Hol canon) source?

{ghorqon} appears to be spelled that way in Hamlet, so I guess that's at least semi-official.

--

De'vID