Unknown - Devonshire Quarrenden?

This is a variety that was supplied to me labelled as Tydeman's Late Orange, but which when it eventually produced fruit over 5 years after planting proved to be an early, red-skinned variety that I've cautiously identified as Devonshire Quarrenden based on the season, appearance and flavour of the fruit. Whatever the actual variety, it is strongly biennial and this year every single flowerering cluster is on a tip, with no sign of any spurs. I've checked the literature on DQ and nowhere does anyone suggest it is a tip-bearer, so I'm back to square one. I have headed it back to about half it's original length. Although it's not a great idea to try to grow tip bearers as cordons (for the obvious reason that it is difficult to keep the growth compact without pruning the fruiting tips away) it is possible, particularly with biennial bearers, which can be pruned back hard in barren years, then the tips headed back in early summer to make a more compact set of tip growth for the following fruiting year. I follow the same routine with St Edmund's which, although it is only supposed to be a tip and spur bearer, has only produced tips for me.