Capture the Flag Variant Rules (Untested)

So yesterday I saw the u/twobats video that u/Mule50 posted, and it got me thinking.

They ran a Capture the Flag scenario, but commented at the end of the video that each of their skirmishes had more or less the same outcome: ignore the flag, wail on the opponent's Planeswalker until someone dies. I started thinking about how, even with the terrain limitations of using only the base set, one could mitigate some of the repetitiveness and make the CtF scenario genuinely tactical and fun. Here's what I've come up with:

Setup is as usual, and each Planeswalker starts on their corresponding Flag token/glyph.

Match length is 15 rounds or n x 15 turns, where n is the number of players (for the sake of this write-up, a turn is a single player's actions, and a round is one full round of the table, i.e. n turns). You could modify the difficulty by increasing or decreasing the number of rounds/turns, but I would suggest a range of 12 – 20.

Play proceeds as usual, with the following exceptions:

• If a figure "captures" the flag, that figure gets +1/+1.
• The flag moves with the capturing figure until the figure holding the flag is destroyed, in which case the flag drops onto the space previously occupied by that figure.
• Players may not hold their own flag with a figure they control, and a player's figures may not occupy the same space as that player's flag (the flag does not block LOS, only movement, and only for the player who owns that flag). This prevents a player from bogarting their own flag with their PW or a tank like the Pummelroots.
• Play continues until either the turn counter runs out or only one player has figures left on the battlefield.

That last point means that even if a player loses his or her Planeswalker, they're still in the game. However, without a PW, there's nobody to cast spells. In my mind, though, all that magic energy is still bouncing around on the battlefield, uncontrolled. That means that:

• When a player's PW is destroyed, that player shuffles his or her hand and places it on top of their Library.
• When a player would ordinarily be able to cast spells (before moving or after attacking), he or she may cast up to three spells, one at a time, from the top of their Library.
• If a spell does not have a valid target or would have no effect, it is discarded.
• If a spell would have a valid target, even if its effects are to the detriment of the casting player, the spell is cast and its effects are resolved as usual.

Ending the scenario:

• If at the end of the match, all or none of the players have captured an opponent's flag, the match is scored as usual.
• If only one player has captured a flag, that player wins, regardless of figure scores.
• In matches with 3 or more players, if 2 or more players have captured flags, players holding flags are eligible for scoring. Players who have not captured an opponent's flag do not score their armies.

I'll be playtesting these rules over the next couple of weeks—today is my wife's last day of work before taking the summer off for maternity leave, plus her parents and brother are flying in tomorrow night, so I'll have plenty of free time and people to try it out with. I'd love to hear some feedback from other AotP players, though—is there anything obvious that I've overlooked? Feel free to test out this variant and let me know if anything is totally game-breaking. Obviously there are some minor caveats that will need to be made with specific armies/figures—for example, Firecats could carry the flag with either space; Jace can't leapfrog the flag when he "jumps" into one of his Projections; etc.

Let me know what you think, and what, if any, changes you might make!