Sure, but there is this fine middle ground between overdoing things in pursuit of the perfect device without ever reaching the lofty goals, and rushing things out the factory because you run out of money/patience/cool. If you don‘t hit the sweetspot, you will either come to the market with a product nobody buys because it‘s just not ready yet, or arrive on the market to compete with Vive 2 and other next gen HMDs (not Oculus, they probably won‘t release their CV2 in 2019, almost impossible for Pimax to be caught out by Oculus even if they add another year of delay).
But I do believe that Pimax will likely consider some of the improvements suggested by the backers as nice to have, and may decide to push the delivery of the 8K if it proves good enough. They can always release an 8K+ in 6, 9 or 12 months from the original one with the improved features, while still being the admired new high-end standard with the 8K in the meantime. That would allow them substantially more time for the refinements and they‘ll earn money in the meantime, which even with tenri series A funding is not to be neglected after a certain period of time.
Assuming the improvements do not concern substantial issues.