"M6 Remap Tool Change: Block Height Issues When Switching G54/G55"

I'm using **manual tool changes with M6 remap** and ER collets (poor repeatability). My issue:  

1. Problem
   - Block height values seem tied to work offsets (G54/G55)  
   - Switching offsets (e.g., G54 → G55) makes tool offsets incorrect  
   - Tool table appears to store work-dependent values  

2. Question
   How can I:  
   - Make tool offsets work consistently across all work coordinates?  
   - Store only pure tool length differences in the tool table?  

Since the collets themselves aren't giving me consistent positioning, I started using the bare spindle nose as my reference point instead.

Here's what I'm doing: First I probe the spindle without any collet installed - let's say that comes out to Z-100 in machine coordinates. I set that as my PROBE HT . Then when I install say, tool T1 and probe it, I might get Z-70, which gives me a nice clean Z-30 offset.