Knights in the Genosian world are expected to patronize a certain craft, and to at least have good taste in it. These are usually hereditary — a noble family will favor a specific field of labor on its lands, and this will often be incorporated into their coat of arms. A knight whose family favors farmers may have a scythe or a sheaf of wheat on his shield, whereas one whose family have always patronized masons may have a tower or a hammer, perhaps with a chisel. Some even roll up their sleeves and engage in the trade themselves from time to time, which is considered a pious endeavor.
Knights are also expected to tithe something to their lord related to their field, so those who patronize farmers may provide grain and supplies on campaign, whereas those who patronize engineers will probably be handed duties to construct bridges or fortifications.
It is sort of an unspoken understanding that the labor that higher nobles patronize are the knights themselves, hence the predominance of martial emblems on their crests.
In the Reich, the most common sort of knight is the Knight-Crofter, whereas in Galli, there is much more variety, from Knight-Tailors to Knight-Goldsmiths. There is a great degree of rivalry between the various knightly factions.
The majority of knights compose a sort of middle class of landowners who are also peers. They have the rights of the nobility, they're allowed to be armed, and they are required to fight in war... But they've got a lot less money, and the upper class sort of looks down on them despite them fulfilling their duties to the letter.
A result of this is that the Knight-Crofters in any given kingdom tend to band together and throw their weight around collectively. They might be near the bottom rung of the aristocracy, but they are still a part of it, and they're smart enough to be aware of the country's direction and what's going on around them politically.
The upper nobility is very aware of what this means for them. Some of them, like King Louis XIX, make peace with the Crofters by promoting them. During the War of the Ninety Kings, a huge number of noble positions were opened, and most of the men promoted were poor knights who had sided with Louis against the middle-lords that had rebelled. Feeling that they were valued, and that given loyalty they might themselves be promoted, the rest of the lower class are content. For now.
In other lands, like the Kaselreich, they rely on the fact that war is inevitable, constant, and fierce. During a war, it doesn't matter how theoretically honorable the Knight-Crofters are, they win glory in war that drowns out any stigma.
In Illegon, simply put, there are very few knights. Illegon never really "did" feudalism. The Legion still makes up most of the military. Knights are rather individuals who serve the Empress or other state officials, their position is not tied to land, and they are rarely hereditary. Groups like the Hematite Order are called knights, but it's just a title.
Jousts, melees, and wrestling competitions are the three stables of chivalric contest in Vosca. However, Contests of Labor are also common. Often, ambitious lords will host events in which Knight-Masons compete to construct at great speed and in good order monuments of ever-escalating grandeur. Obelisks, columns, archways, statues, ziggurats, even small castles spring up overnight as teams of knights and their assistants work furiously to outmatch their opponents. The prizes for these contests are often enormous, as not only do the knights prove their valor, but they also perform a mighty service for the lord holding the event.
Indeed, such events have been used before for cunning purposes. King Henri II of Galli once tricked hundreds of Kamen knights into constructing for him a series of fortresses that he was able to use to hold the border against them the following year, by offering solid gold masonry tools to whomever completed the finest of them.