Yes. From the Subscription Meals Not Yet Selected page, each row has a Manually Select Meals button (shown only if you have the Checkout As module and permission) that opens a normal order for that customer at /admin/checkouts/new?uid=<customer>. Getting into that screen also requires the Edit Customer Orders permission, since that's what the checkout screen itself checks. Once inside, the Subscriptions Meals side-module (used to pick subscription meals) needs the Checkouts As > Subscriptions Meals permission, and buying a new plan there needs Checkouts As > Subscriptions — both also require their matching module. The subscription page's own picker is usually faster for single-date changes.