If your ecu is incapable of giving you good boost control options, then something like this would do.

It claims to offer boost by gear, boost by rpm, or boost by vehicle speed. Obviously you need to provide that information to the controller.

gear would need a speed reference.

So in the absence of a suitable speed signal, boost by rpm would allow you to tailor torque/boost by ramping it in.

If you make large changes to your existing boost patterns, you will need all the tuning re-checked to ensure everything is safe.

There are other controllers out there that can offer similar...usually much higher priced though

https://sirhclabs.com/

There are also lots that make similar claims...but fall short feature wise. I've never used this one, but on paper it looks excellent value for money for such a controller.