Cardano (ADA), EOS, bcash (BCH), ripple (XRP) and tron (TRX) are shitcoins being traded on bitmex.
Apart from BCH none of the rest are shitcoins. IMO i.e
It is not a problem if the customer is fine with the possibility of all of his BTC being sold for one of the shitcoins mentioned above, leaving him back with no BTC but a stack of shitcoins.
Just interjecting here to make a point that even if a customer is left with what you are tagging as shitcoins, the bot (should) leaves the customers with usd equivalence of their BTC investment in those shitcoins + some marginal profits.
And all these shitcoins you mentioned can easily be cashed out on any numerous exchanges because their volume is that high.
And let's face it, OP's bot will never be big enough to take out these multi million dollar worth of
shitcoins from the global market that the customer would be left high and dry.