Copy trading would be also suitable for him if he really wants to be in trading. Long term holding is also good but he needs to practice not checking the price time to time since that could also cause him stress and will lead to problems. It is best if he tries everything (copy trading, holding) if it still giving him problems then probably he needs to find another source of income. Cryptocurrency are really volatile so it would be stressful everyday so it would be nice if you will be staying away on this if he cant control his emotions to be safe.
Copy trading may be good but not sure whether it is suitable for a person who has a heart problem. I don't think it is as easy as you think, mate. Copy trading is also stressful if we don't have sufficient knowledge of it. I am sure the long-term investment is still easier than copy trading. Even newbies can easily understand, they only need to buy during the bearish season and sell in the next bullrun season. It even doesn't require deep practice, right? 