Many Customtone patches are set very high and promote clipping.
A few ideas...
if you use the 1/4 output, try setting it to instrument rather than line
if you use the xlr out, set to mic, not line
set the input pad to ‘on’.
All the above are in Global Settings
Then, on the patch, add a gain block at the very beginning of the signal chain, set to -10db (at least initially, though it may only need -5db to control the clipping...it all depends on the patch itself)
add another gain block at the end set to -3db.
If you do all this the patch will be quieter but should create no clipping.
If you get some patches from someone like fremen, he sets them up carefully to avoid clipping. You can use those as a guide as to how loud a patch might ideally be.