Hi Sticky-Hands and welcome to the Chiu-Ying Forum.
Generally as you point out most Wing Chun is below the waist, but in practice I think its definately good training to Kick higher than you normally would in actual application.
And providing you still incorperate the same Kicks but simply increase the level of their focus, you certainly shouldnt adopt any bad habits that could cause you problems at a later date in your training.
I think it will only make your normal Kicks easier to apply, with better overal Balance, Co-ordination and Impact Power.
Jin-Ka