After both XMR and XDN anti-ASICs forks, merge mining feature has be recovered by a pool
https://xmr.minercountry.com/.
No limits or special arrangment for your miners are required; only is required to use your pub key XDN as password to be payed.
Mind Minergate and Freewallet had not forked XDN blockchain to rel 5 yet, so you'd better use official GUI XDN wallet where you own bot pub and secret key.