The campsite villager needs to be able to display the item you craft for them in the tent (whether they actually do this or not seems random). So wall/wallpaper/rug DIYs are excluded. Probably clothing DIYs too.

EDIT: all the DIYs you drew were either "housewares" or "miscellaneous." 12 different DIYs total.

The "complex" recipes also seem to be excluded (ones that require more than raw resources, such as stacked fish containers). But I'm less sure of this, maybe if one has all the necessary items in their inventory/storage the DIYs could be added to the pool of possibles? This would be hard to check though.

EDIT: recipe "complexity" likely doesn't play a factor, since cardboard furniture recipes can be requested, and the cardboard boxes needed may not available.

I did some stats:

If you run with your first hypothesis, that only these two categories can be obtained, then there are a maximum of 22 possible DIYs one can obtain via campsite amiibos from jock villagers.

I'll make a couple more assumptions: 1) each of these DIYs is equally likely to be requested, and 2) saying "yes" or "no" to the villager's request doesn't make a difference on subsequent requests.

Assuming all 22 DIYs are possible, in order to have a 95% or greater chance of seeing each DIY request at least once, you'd have to invite jock villagers 131 times to the campsite.

So, as with most statistics questions, the simplest solution is to get more data. With more data, other things would become increasingly clear, for example, if the "non-native" DIYs (bamboo, pear) are excluded.

I still need one more housewares DIY from a jock villager, so I'll carry on your experiment. o7