update last_render in case of change of any element, not just number of them optimize for hover/select/highlight where number matters
update last_render in case of change of any element, not just number of them
optimize for hover/select/highlight where number matters

SymbiFlow/nextpnr,YosysHQ/nextpnr,SymbiFlow/nextpnr,YosysHQ/nextpnr,SymbiFlow/nextpnr,SymbiFlow/nextpnr,YosysHQ/nextpnr,YosysHQ/nextpnr