In addition to the comment reeshau made, what you're describing is also market timing and has those disadvantages: you're likely to be suboptimal in your choices about when to sell and when to refill, and you also might be stressed out about making those decisions.
On your question, there are several techniques to consider.
The easiest is what reeshau mentions: Take the withdrawal but don't necessarily spend it. There might be some tax inefficiency because you'd pay taxes on money you didn't need for some years...eh.
Another option is to consider a Roth conversion ladder. Other than the hassle of priming the pump by having 4-5 years of spending available before starting, it is much more flexible than an SEPP program. I was planning on SEPP for years before I read about Roth conversion ladders; I decided to switch because I already had the pump already primed.
You are allowed a one time switch to the RMD method. So you can always do that if your IRA is getting small enough to worry about. This means that you just are exposed to normal SORR risk and there is no additional risk because you happen to be doing an SEPP.
You can also have multiple SEPPs. To do this you would need to split your IRA into multiple IRAs. The technique I think that works best is to split your IRA into two: a smaller IRA sized to provide you with the withdrawal amount you want based on the highest interest rate permitted, and a larger reserve IRA. Start the SEPP on the smaller IRA. If it's ever not enough spending-wise, then split the reserve IRA and start a second SEPP. Lather, rinse, repeat. If you want to get super complicated, each IRA can have a different SEPP: different interest rate, different start date, different IRA size. Since you're married, you can also obviously do this separately for both spouses - i.e., your spouse can have a different SEPP plan than you do.
The RMD method, while producing the smallest withdrawal relative to the size of the IRA, does get recalculated every year, so just using that method would help with the ebb and flow - smaller withdrawals after a bad year, larger withdrawals after a good year. This creates another issue, which is to make sure your lifestyle is funded even in the down years.
Another general principle is to build up more margin. I have a WR of 1%, so I don't worry about SORR.