Multi-Constillation Support for custom Sentences

[JasonPittenger]

Can you expand the custom sentence extraction to support multiple systems?

For example, I'm looking at VDOP that's coming from the GSA sentance.
I'm using

TinyGPSCustom	vdopGP(gps, "GPGSA", 17);

However, I am also using Beidou Navigation Satellite System (BDS) BD, Global Navigation Satellite System (GLONASS) GL and Global Navigation Satellite System (GNSS) GN.
So I really should use

TinyGPSCustom	vdopGP(gps, "GPGSA", 17);
TinyGPSCustom	vdopGN(gps, "GNGSA", 17);
TinyGPSCustom	vdopGL(gps, "GLGSA", 17);
TinyGPSCustom	vdopBD(gps, "BDGSA", 17);

And manually combine the values somehow.

Is there a way to add a custom extraction that works for multiple systems?
As in, the command would only ask for the sentence type and not the system prefix?

For example:

TinyGPSCustom	vdop(gps, "GSA", 17);