Ignoring the compound, just looking at tire tread patterns. What would you prefer for use on grass - square blocks, or round spikes?
I guessblocks will last longer in any environment as they are chunkier and each block is typically larger and sturdier than a spike, on most tyres I have seen. So the loading will be less per block. But which pattern gives the best grip on grass?
Of course there is the halfway between answer - square TQ spikes
To be honest I don't think they would. Generally there is too much grip, especially side bite on grass. Usually I cut off the outer rows of the mini spikes otherwise I will grip roll in high speed corners.
If you're talking about racing competitively with them. I usually get maybe 4 meeting out of a set of rear minispikes before they drop off too much. So that's 16 races for me. You can rejuvenate them though half way through their lifespan by snipping the top off the spike, the more rounded (on top) the spike gets the less grip they generate. I find that if you nip the top off them with nail clippers, you can get a few more runs out of them. On UK tracks yellow minispikes are virtually the number 1 choice for dry tracks, it's great because since almost everyone uses them, it's like a control tyre.
As to whether blocks are any good for other types of track I have no idea really. The tracks I race on are astro/grass mixes. The astro adds another dimension though, it can be tough to get the balance right on mixed surfaces, especially if the grass is worn and dry. In the wet, minispikes are terrible on astro turf, so the tyre of choice becomes ballistic buggy minispikes in green compound.