The only down side I have experienced is the price volatility of Bitcoin. This has a huge effect on the business, because you need cash to run the business. Do you convert to fiat immediately or do you hodl the crypto payments you receive? If you choose the latter, how do you keep record of your actual profits?
What is the average percentage of customers you have that pay with Bitcoin, LN and other cryptocurrencies?
If that number is significant you could convert one part of your coins to fiat currency, but you keep other part in Bitcoin.
This way you could save a lot on fees that could be much higher if you constantly convert BTC to Fiat.
In case if only small percentage of your customers pays with Bitcoin, than I would just hold Bitcoin at least few years before selling.
Yes if few people are using Bitcoins to pay you, then I would also advice you to hold the Bitcoins.
No need of selling them instantly and waste the major portions in transaction and conversion fees.
And also glad to know that you have integrated Bitcoins payment in your store. It would be great if you can tell the stats of how many people on an average use that and are you happy or not when people finds that they can pay you on your store through Bitcoins.