As long as your batteries are adequate, and securely wired to the panels, there is no problem. The batteries will take every thing over the voltage needed to charge as amps.
The batteries are very good voltage regulators. The risk would be that if the batteries should be disconnected from the panels and trailer (loose wire or blown fuse) the trailer could be over volted, such things as circuit boards on furnaces, radios & fridges could be damaged.
Charging systems need a regulator and if you know what you are doing you can do the job yourself.
In the 1980's built 600 wind turbines for marine battery charging, controllers were 20
virtually non existant and were very expensive, if you could find someone to build you one. for 4 years we lived with one charging 2 8D batts, my turbines were capable of putting out 20 amps at 16 volts. We, nor any of our customers (to my knowledge) ever had a problem with over cooking batteries or any other component.
When we first started rving went for several years with no regulator, then because we had over 600 amps panels and controllers had become less expensive we installed a couple on our coach. We put one on our Toyota Sunrader, and will put one on the Boler
when we get around to it. Bought one but don't like it so next fall
will pick up a better one and install it as we travel.
So my experience with battery charging dates back to 1981, and have never had a problem with using or not using a controller. If you are not prepared to be the controller install one. You asked.