Right now it's more practical for me to gamble with stablecoin, since Stake is paying the signature campaign through Tether currency. If I have to convert it into Bitcoin or fiat in order to gamble, it means I will be wasting some money through taxes which can be completely avoided if I just use the USDT currency. But some time ago, when they were paying through BTC currency, I prefered using Bitcoin to gamble for the same reasons stated above.
If I had to deposit money at the casino to play, I would choose Bitcoin, though. It's more convenient when playing at online casinos when compared to fiat currency, which is heavily traceable and taxable by local regulators.
I don't get the issue with taxes while converting the money you received.
In most countries receiving a payment for posting would be taxed, if you then convert it to another form of currency, say Bitcoin to USDT or whatever, then you wouldn't be paying tax again for that conversion since your cost basis is basically the same as the price. So, in reality, in terms of tax it doesn't matter if you use the same coin you received or you convert it to something else, the tax is basically the same.