23c I know some airframes acquired from other airline had T/R fitted but for commonality they used to either wired shut or not permitted to be used, maybe this has changed?
If I recall the original order was placed without T/R fitted because of the problems that bmi had with the F100 which required a tail spar inspection if they were used in anger?
So the 145’s turned up and it was quickly discovered that removing the T/R units saved 125kgs a side this left the CoG so far forward that on the business hand baggage route they had to carry 220 - 330 KG’s of building site blocks, these stayed on 24/7 so with light loads if was often tail heavy.
I’m sure the AAIB will drill down quickly to what happened