TrueType Manual Hinting confusion

I’ve read the tutorials on hinting, but I’m a bit confused. My font is very geometric, with consistent stem widths. It will have 6 static weights, but only 2 are actually made (Bold and ExtraLight).

It’s going to have several different outputs:
Output 1: TrueType with old style kerning for PowerPoint - in 6 weights
Output 2: Variable TrueType/OpenType for use in inDesign
Output 3: Webfonts

I understand that TTF autohinting on export isn’t compatible with variable fonts, so I think I have to do manual TTF hints.

I’m confused about hinting the main master only, and not both. How can this be?

The 2 weights have very different stem widths, the x-height is slightly different, and the overall width of letters is different. If we only get hinting from one master, how can this work?

Question 2:
If I’ve set up TTF zones, should I add hints to each glyph, or is that necessary?

I’m in Glyphs 3.2 (3180). Screen caps are attached.

I should also say how much I love Glyphs. It’s crazy fun to work in, and I’m enjoying learning new things with it.

Many thanks!

Please read the tutorials about hinting.

Manually inserted hints only need to be in the first master or the master you specify with the custom parameter Get Hints from Master.

For variable TTFs InDesign, consider no hints at all. The implementation of TrueType instructioning in Adobe apps is not worth it.