(The language is a little old-fashioned, as if the writer learned to read largely from formal century-old texts.)

He is a loyal citizen.  The Queen is Galtan and Good, so she would approve of him learning about the Foundational Laws of Galt.  Good people do not do Traps and are careful about their tests, and as a loyal citizen he has nothing to fear from a test.  Iomedae is a Good God, and he is striving for Goodness and not thinking about how hard and expensive actually being Good would be.

His stipend means he doesn't have to work all day with cantrips, and he hasn't been trying hard to sell his 1st circle spells either, so an hour and a half isn't much for him, if anything he is bored.  He would stay for 12 hours if it meant his loyalty was proven.  He'll go to the first session and immediately report any heresy?

The sign looks interesting.  She'll tell Thea.  Will he take non-delegates?  She regularly makes 30 silvers off just a pair of 1st circle spells almost daily and her school debts are paid, so she doesn't have to hustle with cantrips, and her idle bit of magic research doesn't take up too much time either, so she'll blow an hour and a half on something novel.  Worst case, an hour or two wasted and she doesn't come back unless it's a loyalty test and she proves her loyalty with diligence.

Thea's actually already managed to get a copy of Galt's constitution* and read it, so this doesn't sound very critical to her?  (She wouldn't mind an explanation on some of the more technical language?)  The other delegates might be idle with nothing to do outside their home city, but she still has students to train and books to read and plans to make, so 90 minutes (plus a bit of walking, but she can arrange any nearby errands) every other day is on the borderline of time she is willing to spend.  And if it's open to even illiterate delegates, the quality of discussion might not be high.  At the very least, she can attend the first session in person with one of her students (and Estella apparently?), to meet other delegates if nothing else.  And if it looks moderately useful, she will send a student to every session, if not herself.

She'll pass the word on to other delegates she knows as well.

*Thea does not realize this copy is no longer in effect, and in fact dramatically failed.

She knows she isn't as combat capable as many of her Sisters (despite being one of the oldest), or as forward thinking as Thea, or as socially adept as Dia.  So she's pleased when Thea tells her she will attend a politically relevant event with her... and less pleased when she learns it is a reading of long legal documents.  Still, she'll do her best, and take copious notes, and show Thea she is capable of more than just combat.  And she doesn't mind a short break from endless sparring and exercises (even if Thea has added more variety and reduced the lethality since she took over).