I increase size by rating, but nowhere near that scale. I see a rating 6 medkit as fitting in a good sized rucksack (similar to a paramedic kit), while a rating 1 or 2 would probably fit in a standard combat pouch or even squeeze in the side pocket of BDU pants.
Having them take up an entire room is completely ignoring the kit, shop, facility rules. I recommend pointing out page 124 of Augmentation to him:
MEDICAL EQUIPMENT
Medical tools, like other tools, are available in kits, shops, and facilities. The medkit described on p. 337, SR4A, can be used on one patient at a time and is quite portable. Portable and nonportable versions of all kinds of medical equipment exist, though shops and facilities are more “mobile” than “portable” in the traditional sense. A non-portable medkit is called a medical station, and
is a staple of hospitals and clinics the world over. Mobile medical facilities are pretty much only found in militaries and places where
the land itself moves around, such as the Trans Polar Aleut nation.
A medical shop or facility has substantially more diagnostic gear than does a simple medkit. In poorer parts of the world, a “hospital” is simply a building with one or more medkits in it. A true medical shop has enough gear that it counts as a Rating
8 medkit. A true facility has enough gear that it counts as a Rating 10 medkit. Such quality comes at a price greater than the
extra space and nuyen: medical equipment beyond the medkit is substantially less “idiot proof ” and provides no bonus to untrained
individuals.
While a shady black clinic might contain only a single facility or even a shop, major hospitals usually incorporate many
shops, facilities, and stations. For example: Tacoma General Hospital has 117 medical stations (Rating 3–6), 29 medical
shops, and 6 medical facilities. On the other end of the spectrum, Dr. Glenn Swayne operates a single medical facility in the San
Fernando Valley.
If it takes up an entire room for a rating 6, there is no point to not just toss the extra cash in for Medical Shop and treat it as a Rating 8.