What is the "risk" you are worried about? As explained above, the Eheim Classics have a more simple design with less bypass, making them better at actually
filtering. However, your priority seems to be
turnover (as it should be for a typical lightly/medium stocked planted tank), and unless you have big messy fish kicking up silt, or a heavy bioload and poor plant growth, I would persoanlly advise considering ease-of-maintence and turnover rate over filtering efficiency.
So I wouldent say the higher bypass in the Fluval 105 is a "problem" at all, if you are putting a 105 (designed for a 100l tank) on a 45l tank, it's still going to have way more capacity to filter bits out of the water than you actually need, and more than a typical 45l tank would have. One of the reasons the flow rate is faster in the Fluvals is because of the bypass. More bypass = less efficiency = higher flow rate for the same size of pump . The more efficient it is at filtering, the faster the media will clog and reduce the flow rate, leading to more frequent mainenence...hardly an issue with a 2213 on a 45l since it's a good size of filter for the tank though
.
Efficiency isnt really part of the equation when you are adding external filters and trying to get a high rate of turnover though. This is why many people just use a smaller sized external along with internal wavemakers or powerheads in the tank, which would be a better idea for you than buying a whole new filter if you don't mind extra equipment in the tank.
Additionally 06/07 series do have a slightly better media setup with less bypass, but like I say, I dont care about bypass on planted tanks. I often leave some of the media baskets emtpy just so I don't have to clean the filter out as often 😅(if I left all the baskets full in the 405 on my messy goldfish tank the flow would slow down too fast).