The following does not work in SAS 9.4M3 because the CONNECT USING statement drops option, so I suggest CONNECT USING either remembers the options from the libref or allows them to be specified on the CONNECT USING statement.
libname db odbc required="..." connection=global dbmax_text=8000;
connect using db;
execute (create temporary table temptab1 as select * from permtable ) by db;
/* This fails as the table does not exist because CONNECTION is dropped */
insert into db.temptab1 values ('abcd');
/* This is truncated because DBMAX_TEXT is dropped */
create table truncated as select long from db.long;