These are solutions from our end, it's also possible that Stake chat mods would pick up on this tip spamming and restrict their tipping ability. Since Stake's aware of the bot it shouldn't cause issues for the bot account.
I see that eight cryptocurrencies are working with poorbot, and there are more coins accepted in Stake.
Do you have any plans to add more of them in future, for example solana with other popular crypto, or maybe add a way to send coins to external address with additional fee?