Maximum head pressure is 9 ft, lateral runs do add head pressure but much less. The main problem with long lateral runs is that if the reservoir runs dry, it can be hard to reprime an airlocked pump with a long hose length attached. You have to rock the pump and get the air out while it is running. The ideal way to do what you want to do is to have an RO auto top off to the reservoir and equip the reservoir with an overflow outside or to a floor drain. For example, at home I have a 180 plant tank, it has an osmolator and the 27L reservoir we offer. Inside the reservoir I have our 8555 RO controller which operates on float switches and additionally has a safety time out that will only let the RO unit run for 12 or 24 continuous hours, this is user adjusted setting. I additionally drilled the reservoir near the top and installed a Jaco fitting with a standard piece of RO tubing running through the exterior wall of the house and into the yard, the RO unit is also installed on the outside wall of the house. In this way if the RO unit ruptures, no flood, if the solenoid fails, the water should drain outside after the reservoir reaches a certain height. Having woken up to a 2" puddle from one end of my house to the other due to a broken toilet supply line I am very cautious about flooding, I ruined a Pergo floor I had installed myself and had extensive damage to walls and cabinets and doing it myself it took 2 yrs to get my house back in order. I say I ruined it because my house was on the outskirts of town and I lived in it when it when it was annexed, with city water pressure I had 120psi at the tap and I should have installed a pressure regulator in the main line the day we transferred to the city water supply, with the water tower only a 1/2 mile away the pressure was more than household pipes are rated for. Bottom line, floods can be very disasterous and usually a little prevention is worth it.