I have a vacuum clamp table (Basis Debut). It cannot seal a 10" record. This is not the end of the world. Just turn off the vacuum and use the center sealing puck as a weight. Yes, you won't get the tight coupling of the record to the platter, but, there is no point to having a blank record seal tight to the platter if there is no way to tightly seal the 10" record to the blank anyway.
SME Tonarms, SOTA Vacuum Turntables, and 10" Records
I have a SOTA NOVA V, an SME IV.VI, a Dynavector xx2mk2, and lots of great 10" jazz lps. As a result of the vacuum lip and the tapering tubular tonearm of the SME, playing a 10" lp is not possible because of the lip not making vacuum w/the platter. Hence, I am using a 12" crappy thin lp as a means to make vacuum and I place the 10" on top of the crappy lp. The 12" lp becomes my platter. Being the best fidelity and surfaces of the 10" lps are found on the the Bethlehems and the Blue Notes, their fidelity is not really degraded by the slight decrease in VTA that is a consequence of the increased platter height.
Am I the only one doing this? As far as a blank disc, the only ones I know of are the Johnny Winter Second Winter side 4 and a Mosaic lp set w/an odd number of sides.