You need drains on the rocker covers... The oil has to go somewhere...

The pic is a bit fuzzy but the drains can be clearly seen. It makes no noticable difference whether you have the oil supply aimed at the exhaust valve (forward connection) or intake valve (rear connection),, just do wat makes for the visually neatest solution.

You can leave the drains open and a little bit of oil will soil the sides of your plane, but there is absolutely no issue with rerouting those drains back to the middle exitting at the centre of the firewall, or from each cylinder to a main gear leg if you want to keep the plane oil free.
The only criteria is to use equal; lenghts of tubing so the flow will be as equal as possible. The backpressure does not create any problems.

It is advisable to cut cardboard gaskets for the rockercovers and wrap a bit of teflon tape around the heads of the rocker cover bolts to keep the cylinder heads clean. No biggie, that's a one time affair.
Allow for an approximate 10~20 hours to let the valve lash stabilize, depending on state of break-in.
Mine from new required a 5 hourly check/adjustment up till about 20 hours, then valve lash simply stopped changing, and I basically kept checking every 5 hours until 40, then I decided enough is enough. I check when I change the plugs, which is about every 35~50 hours.
Can't judge your flying intensity, but for me, 25 hours is about a year of use (I have progged a runhour counter that ONLY counts ACTUAL running time based on "ignition ON+RPM<500". So prep-time with RX on, or even ignition on, or anything where the engine is NOT actually running, is not counted)