Max HTLC’s essentially indicates to the network the maximum amount of payment you can/are willing to forward. Let’s say you have a 1 million sat channel but only 321,210 sats on your side. By default the max HTLC’s is set to the channel capacity so here 1,000,000. However because you only have 321,210 sats locally, a forward payment of 1,000,000 would result in a failed payment which decreases the ‘reputation’ of your node to forward payment. Therefore you need to set up your Max HTLC’s to 321,000. That way the network knows that it can only forward 321,000 sats payment or less through your channel ⚡️