hack.js

    this.on('beforewrite', function (store, action, record, options) {
      var proceed = !!(record.event && !record.event.phantom);

      if (proceed && record.createInProgress) {
        queued.push(record);
        return false;
      }

      if (proceed && record.phantom) {
        record.createInProgress = true;
      }
    }, this);

    this.on('write', function (store, action, result, res, rs) {
      Ext.each(rs, function (record) {
        record.createInProgress = false;
      }, this);

      Ext.each(queued, function (record) {
        record.commit();
      }, this);

      queued = [];
    }, this);

untested_queuing_store.js

PathCore.ExtExtensions.Store = Ext.extend(Ext.ux.data.serverSideErrors.Store, {
  pendingRecords: [],

  constructor: function (config) {
    PathCore.ExtExtensions.Store.superclass.constructor.call(this, config);
  },

  execute: function (action, rs, options) {
    var didRequest = false,
        partitioned = Ext.partition(rs, function (record) {
          return record.responsePending;
        }),
        pending = partitioned[0],
        quiescent = partitioned[1];

    this.pendingRecords.push(pending);
    
    if (quiescent.length > 0) {
      didRequest = PathCore.ExtExtensions.Store.superclass.execute.call(this, action, $.extend([], quiescent), options);

      if (didRequest) {
        this.touch(quiescent, true);
      }
    }

    return didRequest;
  },

  onCreateRecords: function (success, rs, data) {
    this.touch(rs, false);

    PathCore.ExtExtensions.Store.superclass.onCreateRecords.call(this, success, rs, data);

    this.resubmitPending();
  },

  onUpdateRecords: function (success, rs, data) {
    this.touch(rs, false);

    PathCore.ExtExtensions.Store.superclass.onUpdateRecords.call(this, success, rs, data);

    this.resubmitPending();
  },

  onDestroyRecords: function (success, rs, data) {
    this.touch(rs, false);

    PathCore.ExtExtensions.Store.superclass.onDestroyRecords.call(this, success, rs, data);

    this.resubmitPending();
  },

  touch: function (rs, activate) {
    Ext.each(rs, function (record) {
      record.responsePending = activate;
    }, this);
  },
  
  resubmitPending: function () {
    var pending = Ext.flatten($.extend([], this.pendingRecords));

    this.pendingRecords = [];

    Ext.each(pending, function (record) {
      record.commit();
    }, this);
  }
});