Dosing pump question

[Opus]

Got a question I haven't seen asked before. I'm thinking of getting a dosing pump setup this year and have a question about height. It seems most people that does have a sump. I don't have one so it would have to pump the additives back up to the tank. Will this effect the pumping in any way? I know return pumps pump less the higher they have to go so didn't know if these would be effected the same way.