Myself and few others worry that xbond pool may bring back the death spiral problem, where xbond gets dumped on market before a negative rebase. so xbond may end up trading lower than the $ value of USD Token. if this happens then there will not be any incentive to buy USD to mint xbond during negative rebase. also dont forget that USD token gets debased during negative rebase. with almost no incentive to mint xbond people may just choose to dump USD on market to stay safe from debase.
there will be a race to the bottom. this means the lower the $ value of USD token goes the lower the value of xbond will follow.
on the other hand look at ESD. ESD coupon is not tradable, that makes sure it can not be dumped during negative rebase and they let you redeem it during positive rebase. but xbond is not fully redeemable here. the difference is that ESD coupon expires and does not get rebase rewards but xbond does not expire and gets a hefty percentage of rewards.
the problem with xbond is that it does not let you liquidate 100% of your holdings without a pool. thats why there is a demand for a pool.
i think better way to do it may be to somehow allow people to redeem 100% of their xbond holdings. something like allowing 1% of the original invested USD redeemable on top of the rewards may help people get out 100% in 100 positive rebases.
Designing a better payout or redeem strategy for xbond is much better than having a pool in my opinion.