Window FrameType By Platform?

I want to do something that I THINK could have been done in REALBasic way back when IIRC, but I don’t see way to do that now.

While I never used it in the past I know that for some fields in the inspector on can use a constant (which can be set to be different by platform) by putting #constantName in the inspector for a value…

IIRC in ancient days on would put the number for the frame type in the inspector so one COULD use the #Constant to set frame type by platform, instead of needing two separate windows. As it is a design time setting, setting it in the Inspector is the only option.

But now the inspector only seems to let you pick from an enum… though the docs still list the frame type numbers.

At first glance that seems to be the best/right way… It would be best for a single platform product… but that is not what Xojo is…

So am I missing something or is there still a way to use a constant for frame type somehow?

BTW What I want to do is us a sheet on mac OS and a plain box (or shadow box) on Windows (where I will show it modal and place it where the sheet would appear if it was on a Mac- so I don’t want it to be a Movable Modal that Xojo defaults to on Non Mac OSes)

BTW I am not asking for a workaround… I know that the workaround is using 2 windows by putting all the controls/code in a container control so at least that does not need to be duplicated.

If it matters, although I have a current licence, I am using 2019 r1.1 as I am sticking with API 1 for now for coding.

Thanks,
-Karen