If you do your research you can find some genuine Tonghui fixtures at reasonable prices, we got TH26009B Tweezers that are OEM. We don't use them very often, altho they are good to 15MHz!!
Yep, the Hioki equipment is expensive, thankfully all the Tonghui fixtures fit and work fine on the IM3536, we made absolute sure of that before ordering
The cheaper no-name SMD fixtures seem OK, especially if you check out, tighten and mod them as we've shown. We fooled around with one and tried to see if we could use it for temperature sweeps by raising the plunger mechanism above the top surface plate and use a chassis mount 10W resistor as the heating element for the DUT. The chip is placed on the top surface of the resistor insulated by polyamide tape, and thermistor is attached just above the DUT area with thermally conductive tape. This kinda worked OK for static temperature tests, but wasn't repeatable for sweeps, and we abandoned the concept. The main issue was the plunger prongs would conduct heat away from DUT and you needed to wait much too long for thermal equilibrium. We even tried to "cheat" by measuring the DUT temperature with a chip thermistor as the DUT, this is how we knew the DUT temperature relative to the heating resistor mounted thermistor, and fitting a polynomial to estimate the actual DUT temperature vs sweeps, but too much uncertainty for our liking, so idea was trashed. Steady state could work but would require very long wait time between temperature changes for acceptable repeatability, too long for our patience
Best,