Thats generally a really bad way to adjust reach. While it will make your distance to the handlebars shorter, it'll tend to force more weight onto your hands and change your pedalling dynamics putting you at greater risk of anterior knee pain.
From experience of owning a vbr099 and a vbr177, the seatpost setback is an issue if not put into consideration when ordering the frame. For me the 099 seatpost setback is so backward that my knees does not track with the center of my pedals at 3 O'clock pedal position. I now run a zero setback seatpost on the vbr177 and this solved that issues and I have a perfect fit (Although my vbr177 stack is about 1-2cm lower compared to my vbr099 which I am ok with this stack).
He said the vbr177 frame "feels a bit too long and low". If I use a seatpost that has a setback on my current vbr177, it will definitely feel long and useless to me.
If his issue is similar to mine then he can try a zero setback 27.2 seatpost which is easy to borrow or buy to test, compared to the vbr099 proprietary seatpost. If it doesn't help then at least he tried it
In my opinion there is no "generally - really bad way to adjust reach" or going about a bike fitting. You solve case by case bases, starting from the back side and then the front side of the bike.
Looking forward to a SEKA bike review soon!