You're doing the right thing - keep him upright for a while after feeds. If it's particularly bad you can ask your GP about getting baby gaviscon
Yes I also keep my newborn upright for 30mins to an hour and make sure she burbs and lets the wind out before putting her back on her cot or Moses basket. I don’t think we can stop the reflux but minimising helps. I’ve also bought a bed sheet that is super soft and soaks up any pukes so she’s not sleeping in wet mattress
Have baby upright for about 30 minutes after he finishes feeding as this will help the milk to settle, also make sure to wind him as well as this will also help, with my firstborn i used to get halfway through a feed, stop to wind, let him finish the feed and then wind again up on my shoulder, after this i would keep him upright for around 30 minutes and this would help x