Larger models better understand and reproduce what's in their training set.
For example, I used to get verbatim quotes and answers from copyrighted works when I used GPT-3.5. That's what clued me in to the copyright problem. Whereas, the smallest models often produced nonsense about the same topics. Because small models often produce nonsense.
You might need to do a new test each time to avoid your old ones being scraped into the training sets. Maybe a new one for each model produced after your last one. Totally unrelated to the last one, too.
because generating nice looking svg requires handling code, shapes, long context, reasoning and at 2b you most likely will break the syntax of the file 9 times out of 10 if you train for that. or you will need to go for simpler pelicans. might not be worth to ft on a 2b. but on their top tier open model it is definitly worth it. even not directly but just crawling a github would make it train on your pelicans.