Apologies - I was too hasty, knee-jerk reaction to the overloaded word "task"; yours are features.
Your real limitation here is Trello. With other tools (or just a whiteboard, often a good option) you'd put your bigger features into horizontal swimlanes, and you'd take care never to have more than a manageable number of those in progress at any time. Finding stuff isn't hard therefore.
Turning it inside-out as you've done here is clever. The tradeoff is the focus on a limited about of work in progress, and with that, focus on completion. So you'll need to find ways to review the equivalent of right to left, most complete first.
Your real limitation here is Trello. With other tools (or just a whiteboard, often a good option) you'd put your bigger features into horizontal swimlanes, and you'd take care never to have more than a manageable number of those in progress at any time. Finding stuff isn't hard therefore.
Turning it inside-out as you've done here is clever. The tradeoff is the focus on a limited about of work in progress, and with that, focus on completion. So you'll need to find ways to review the equivalent of right to left, most complete first.