[Archon Intensify] gives an extra 30% and Molt [Vigor] gives an extra 45% which are not accounted for on Overframe, giving a total of 548% strength on demand.

Other conditionals can further elevate power strength:
Madurai - 40%
Power Drain - 50%
Pax Bolt - 30%
Archon Shards - 10% each normal shard or 15% tauforged up to 75% max
Nidus Specter - 1.28x

This gives a maximum on demand strength (without relic buffs or team buffs) of 743% before [Nidus] link and 951% strength after [Nidus] specter link.