Or is it better to increase the gap limit.
I don't see any difference when it comes to a cold wallet.
The first command I mentioned increases the gap limit and the second command generates more addresses without increasing the gap limit.
Note that the default gap limit in electrum is 20 and that means that electrum gets the transactions history of addresses one by one and it stops when it reaches 20 consecutive unused addresses.
You can ask addresses to increase the gap limit.
Lets say someone inherits this wallet seed. How do they know when to stop generating addresses to find the value of the wallet?
If you want to fund your wallet now, use the first address. The next time, use the second address and so on. In this way, there will be no problem in the future.