Good question - and you already got the reply
Many years ago, we seeked low wind days, using bigger special wide low rockered waveboards, and big kites - and then it was freeraceboards that could easily top any lightwind waveboard.
It was great fun back in the days, as it was the ultimate way of riding on sunny beautiful days with quite low wind
a few used HUGE foilkites and big TT boards - I have no idea why, and I still dont understand it, makes absolutely no sense IMO as it is plowing back and fourth and nothing but that, compared to what other boards can offer of livelyness and fun
Sorry to offend some, but I really think it is beginners or those who are not really progressing that do this
Back to the question - you asked "with a big kite" ?
You can cancel that, and drop the big kite you dont NEED a big kite when hydrofoiling, that is a huge advantage.
To ride in 7 knots on a hydrofoil, a 12 m2 LEI is sufficient, and you hardly ever see anyone using bigger than this.
For marginal winds, yes, but that is not what you ask for ?
The other huge difference is, that with a hydrofoil, the 8-10 knots is the sweetspot playground wind where everything is possible and quite easy - and the most amazing fact with a hydrofoil is, that you DONT wish and want more wind, to have more fun - it is fun in all windranges - quite opposite to TT og Waveboards where more wind equals more fun and options
So no, they are not even close to being the same, lightyears apart