For sure, here are the registers used for each fraction:

  comp h^2 > comp H^2
  comp h c > done H
  comp     > done c^2
  done H^2 > done h^3
  done H   > comp
  done     > comp

  Accumulator: comp h^8

The first two does the comparison for odd/even, the h register is moved to the H register during the comparison, then done does H += H>>2, and then keep trying.

https://wiki.xxiivv.com/site/fractran.html

And 297/275 to 27/25?

Conway's Fractran traditionally compares the accumulator against reduced fractions, but computationally-speaking, getting to the gcd of a fraction does little more than getting rid of otherwise valuable information used during comparison to match against a restricted set of fractions. The support for catalysts, symbols found on both sides of a rewrite rule, makes for a simpler and faster implementation.

  15/6 red [green] > blue [green]
  5/2 red > blue

  red green

These two fractions are not equal and reducing the first into the second, eliminates the capability to match against it only when the catalyst green is present in the accumulator.