Hi,
I have added "paymill" in the payment plugin TODO list.
We don't have any plans for this specific payment plugin. The API looks good but when have a big list and I can't say when a plugin would be integrate, if we did it.
If you really needs this payment plugin, you can
contact us
for an inquiry.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.