I know what you mean... If you feed your fish daily adding some (perhaps pre-measured) ferts at the same time isn't a big issue. I used to do that, and hated it...
The goal is to find something that you don't
have to fiddle with. The water pump dosing is a very good example - cheap and easy to set up, and minimal maintenance on the long run. Every 4 weeks I refill the container, that's it. Running the pump for one minute a day does not wear it out, uses close to no energy, mixes up the solution, and is very reliable. I just can't see much reason not
to do that, even for larger tanks.
I might be a little extreme, but I am having fun fiddling now to go near maintenance free for the long term. Looking at 3 of my tanks, this is what I am using:
(10) Water Pump for N+K, (4) Syringe 2 for Micros, manual for P. Will be using (8) Peristaltic Pump for Micros, and (2) Test Tubes for P.
(10) Water Pump for N+K, (4) Syringe 2 for Micros, manual for P. Will be using (5) Airpump 1 for micros and (2) Test Tubes for P.
(2) Test Tubes for NPK, (8) Peristaltic Pump for Micros.
This setup is/will be reliable, and I only have to spend maybe 1/2 hour every 4 weeks to check fillstands and replace mixed solutions.