KAB is a USA-based company who've generated quite a following with their SL1200 upgrades. Their are many threads here and on other forums with 1200 owners trading tips & experiences regarding which upgrades were most impactful.
This wave of excitement kind of died down when the G was introduced, as I believe a number of the enhancements were accounted for by Technics in the new build.
Definitely, because KAB upgrades are for cheap and old SL1200 mk2, mk3, mk5 and related popular models from the past. Those models cost no more than $300 secondhand and that was a price tag for decades. KAB never specialized in upgrades for high-end SP-10 mk2 or related models.
There is nothing to upgrade the reference turntable in SL1200 series, such as SL1200G with retail price nearly $4k.
For audiophiles an upgrade is always an option. Tonearm upgrade is an expensive upgrade, to beat new Technics tonearm you could pay more than new "G" turntable. If one thinks about different tonearms then SP-10R is much better for that needs, because the SL1200G was introduced as a complete turntable.