theoretically, there is no risk because as long as there are daily revenues the system will keep fast tracking the next member in queue indefinitely.
100% of daily revenues are used to fast track members who invested in 186/250% plans
but there is a possibility of a slow payout time.
it all depends on the daily revenues and the created debt of the site which you can monitor every day in daily results section.
if those 2 are very unbalanced e.g. debt too big and daily revenues too small it would take too much time for the system to pay you out, in that case debt swap would be performed
(wiping out all debt and turning all money into shares, calculated by summing up mtv/pv's created debt+member's balances+fast track plans+converted bap and dividing it by current total number of shares in circulation) as it was the case this year somewhere in late January I think. You would still have your money, but in shares, all you would have to do is sell the shares.
Right now you have no reason to worry about it because the system is completely liquid,
daily revenues are reaching new records(except these few days of pv downtime) and I say go for it since the plans fast track ETA is below 100 days