That's awesome! I don't think 2500 is bad.. not sure about the 1%... maybe a flat fee for any tx or per input - say different ppl tipped 5000 + 5000 + 2500 - would be a bigger tx.
I will consider to use different flat fee levels for sum ranges. As for inputs, for memo pay its indifferent who has tipped, it wait for amount from invoice, so it can be group payment
