

Q1: What does the "players can't gain memory other than by Tamer effects" effect do, exactly?
With this effect, players' memory will no longer increase by any effects except Tamer effects. This effect affects both players.
Q2: Can I gain memory using an effect on a Tamer that's treated as a Digimon with X000 DP due to an effect while my opponent has "players can't gain memory other than by Tamer effects" activated?
Yes, you can. When an effect is activated on a card that's treated as both a Digimon and a Tamer, the effect is treated as both a Digimon effect and a Tamer effect, therefore you can gain memory.
Lv.3 Hyemon BT25-079 C Rookie | Data | Beast/BEATBREAK [All Turns] Players can't gain memory other than by Tamer effects. --- <Retaliation> (When only this Digimon is deleted in battle, delete the Digimon it battled.)
Lv.3 Hyemon BT25-079 C Rookie | Data | Beast/BEATBREAK [All Turns] Players can't gain memory other than by Tamer effects. --- <Retaliation> (When only this Digimon is deleted in battle, delete the Digimon it battled.)
Lv.3 Hyemon BT25-079 C rookie | Data | Beast/BEATBREAK [All Turns] Players can't gain memory other than by Tamer effects. --- <Retaliation>
Lv.3 ハイエモン BT25-079 C 成長期 | データ種 | 獣型/ビートブレイク 【お互いのターン】お互いはテイマーの効果以外でメモリーをプラスできない。 --- ≪道連れ≫(このデジモンだけがバトルで消滅したとき、バトルした相手のデジモンを消滅させる)