RedRambler

Long time cyclist, but first time trying to build one up from a gravel bike frame - titanium, so bit of a newbie. Frame / derailleur question.
I'm having a bike frame custom built and have the option from the builder for front derailleur mount of 1)none 2)standard direct mount 3)E2 Direct Mount 4)Shimano high direct mount

My main issue is selecting one of these (or none). I'd like to have a 2X Shimano GRX (or possibly Ultegra) drivetrain installed, but not sure due to availability or price at the moment that it will be the first build for this frame. I have another lightly used Shimano (tiagra) 2X drivetrain on another bike that I thought about taking off and using for now, but it is not a direct mount derailleur.

If I have the frame custom made with a Shimano high direct mount - thinking to the future - I assume that "gets in the way" of installing a standard / older front derailleur. Is there an easy way to at least for the short term - install a standard front derailleur that I have on a frame with the Shimano high direct mount? If so, what is that solution / work-around? Other recommendations? Thanks!

Crankycrank

Since it's a Ti frame I'll assume you have a round seat tube and can mount a clamp on derailleur so IMO go with no mount for a clamp on. Makes things easier if you decide to go with smaller/bigger chainring, future changes to new derailleurs that may call for higher or lower mounting that's out of range of a fixed mount, etc.

icemilkcoffee 

On a painted frame I would definitely go for direct mount because the clamp is hell on the paint.
On an unpainted Ti frame either way is fine.

bOsscO

This. Although if it was me, regardless of paint, I'd go direct mount.