Uso de condicional para pedir algo

En un artículo en inglés https://www.realfastspanish.com/grammar/the-spanish-conditional-tense-5-uses leí lo siguiente (en los puntos 1 & 2):

"You need to be careful with the use of the conditional tense when asking for things in say a restaurant or a shop. In English, we ask for things as follows:

I would like to have a glass of water.

When I was in Sevilla I went into a tapas bar and asked for a ‘tortilla’ (Spanish omelette) as follows:

Me gustaría tener una tortilla. ⊗

The guy behind the bar looked at me with bewilderment.

Apart from my errant use the use of the verb ‘tener’ in this context—it may appear as more a philosophical question in Spanish than anything else (can I actually ‘have’ a tortilla?)—the conditional tense is only really used in the present for expressing politeness. While you could say ‘querría una tortilla‘ it is much better to use the conditional tense for desires that are a little more far-reaching than a plate of food just over the barman’s shoulder.

…In contrast to the previous point about asking for food in a restaurant, there are, of course, times that call for politeness.

In general, the Spanish language tends to be far more direct than English. But, there still remain situations such as speaking to a police officer, a doctor or asking for a big favor from a friend that require a touch of courtesy.

Something else to consider is the use of the usted form of the verb when you want to be polite. Simply using the usted form in Spanish expresses an idea in a more formal way. You can, thus, and probably should combine the usted form with the conditional tense.

Would you have any information about my son’s case? = ¿Tendría alguna información sobre el caso de mi hijo?"

Lo que explicó el autor, ¿es correcto? Especialmente sobre la escena en un bar donde es mejor no usar condicional? Pregunto porque vi algunos ejemplos:

"Sería tan amable de acomodarse en siento, Jose?"

"Me gustaría ver el menú, por favor."

P.S. Por adelantado agradezco que corrijan errores en mi pregunta en caso de que los haya.