Hi @stevenh , yes we did solve it.
environment variables all the way 
# The maximum time, in milliseconds, that pool will try to get connection before throwing error. retool had it set to 100.000ms = 100s = 1.5~m
SEQUELIZE_ACQUIRE=3000
# The maximum time, in milliseconds, that a connection can be idle before being released. retool had it set to 100.000ms = 100s = 1.5~m
SEQUELIZE_IDLE=2000
# The time interval, in milliseconds, after which sequelize-pool will remove idle connections. retool had it set to 1.000.000ms = 1000s = 17~m
SEQUELIZE_EVICT=3000
# Maximum number of connections in pool. Default is 5, retool did not have it set
SEQUELIZE_MAX=100
# The number of times to use a connection before closing and replacing it. Default is Infinity, retool had it set to 1.000.000
SEQUELIZE_MAX_USES=1000
This has kept our connections at ~100.