It would be very useful to give us a facility in Rune Temple to exchange/convert yellow tier runes into fragments at either a fixed exchange rate or a random exchange rate.
Given that it costs 20 fragments to purchase/convert to a yellow rune it seems more than fair to let us go the other way to get at least 5 rune fragments by turning one in to be de-constructed/broken into fragments. If a yellow rune has levels higher than one then maybe increase the exchange rate so that we get more additional fragments as compensation for the higher level.

The best option though would be to give us an option in the Rune Temple to turn off yellow runes completely when calling on the Rune Master to give a higher probability for getting only fragments. I could envision a check box button instructions to the Rune Master to perform his magic in one of the following modes or combinations of modes: e.g. Make Runes [x] Make Fragments [x] where we could set the check boxes to have him try to make only Runes or only Fragments or Both Runes and Fragments with a corresponding roll-up/roll-down of probability that is perhaps also reflected back on the screen with an indication as to how that effects the probability (e.g. 2%, 3%, 2.5%)

This need scenario comes into play a lot when trying to get to the 100 fragment class of dual-bonus runes such as Vengeance and all we seem to get is a long run of yellow tier runes which duplicate the runes we already own. Rather than just always combining and wasting the excess yellow runes let us down-convert them into fragments. If we are paying the Rune Master for his services we certainly would not ask him to produce yellow runes when we do not need any when our objective us only the dual-purpose class of runes or fragments. The other way to do this would be to give us an option at turning off standard yellow rune generation all together and increase our chances for rolling a dual-tier rune directly. So lots of different ways to implement this idea.

Question: Anyone know if when in the Rune Temple its even possible to random roll a dual-purpose rune like vengeance directly? I have never seen or heard of it happening in game.