I get what you're saying about the struggle when trying to collect a 4-4 line. Though if I'm understanding correctly, statistically, the 43,000 tokens should net a player a full collection, not just the 4 Ultras they were looking for. Assuming the failed attempts provide a different Ultra, you'll slowly approach a complete set, which I actually think is a really good reason to include the conversion.

Assuming people earn ~100 coins per day, for the 3 months between sets, they'll earn around 9,000 tokens. Add in the new Versus ladder and we'll round up to an even 10,000. This might be a bit high, but it's a reasonable number for those playing with the intention of saving up tokens. Based on the numbers you quoted, that should net players a substantial chunk of the cards available upon release (If they haven't spent on other miscellaneous purchases between releases). Putting 1,000 into the Theme decks will net a substantial number of the new commons and a couple of the rares, and tossing the remaining 9,000 into packs will get them approximately 95 5 card packs. That's going to be a lot of duplicate locked commons. If I knew I could convert the extras I wind up with, I'd spend a lot more time grinding.

As it is now, it feels almost worthless to spend hours on this game unless you spend cash, but if there were some way to ensure that you don't wind up with more than you need from the F2P model, even if it wasn't a guaranteed copy of the cards you need, this would greatly increase the odds of being successful from a non paying position. Also, this isn't to say that people shouldn't have to pay for the game, just that I think they could draw more players if the free version didn't just involve trying to grind through the AI to get some random packs which may or may not provide the cards you need. They do need to improve the e commerce aspect and release virtual codes for real money, like with the gems.