The Build Notes discuss several options for controlling the output level. Changing R13 to 68K when using TR2 should give plenty of gain to achieve unity level using TR2. If R13 is 22K and TR2 is used, you will not be able to reach unity level until TR2 is fully CCW.
The published parts list calls for R14 to be 22K. R13 is listed as 68K. The Build Notes suggest R14 should “try 22K to 33K if needed.”
Changing the TIME pot taper from a B100K to a A100K is certainly a personal preference. Likewise changing R9 from 1K to 6.8K will provide more emphasis on the shorter delay range. The Build Notes discussed the delay time relationship of the resistance values of R22 as well.since most users seem to be more concerned with achieving longer delay times rather than the shorter ones.