It is possible to override the mode setting done by Easytrieve Plus by using the RMODE and AMODE link-edit PARMs in the JCL.
Easytrieve Plus Report Generator, release 6.4
This is not recommended, however, because setting AMODE to 31 in the JCL link-edit parms sets the high order bit 'on' in a register that might be used for another purpose. This VCON problem will be rare, but needs to be mentioned as it is not easy to detect if it should occur.
Basically, do not code any MODE information on the LINK and take the defaults that Easytrieve Plus is passing: AMODE=31 and RMODE=24.