The fees spike is understandable due to the decentralized nature of Bitcoin and will occur with every change in the price, but such a spike will not affect the fees in the long term because it will be in less than 60 blocks and the fees will return to normal after several hours. The continuity of the spike will be due to things like injections, which we seem to be responsible for causing high fees so far.
In your estimation of the appropriate fees, although the recommendations on mempool.space are useful, but if you take a deeper look at mempool, it will save you more fees.
Of course, I always use the mempool to transact. Mempool is quite helpful. But there is something I am worried about, when the price reaches the new ATH later. There are concerns that transaction fees will cost me. The problem that the Ordinal network has entered a saturation period has made transactions return to normal. I feel happy with this condition even nowadays 12sat/VB is quite cheap price. If later Ordinal is crowded again and ATH comes, I don't expect transaction fees will not reach the new ATH.
Well expect that to happen since there are lots of people want to move their bitcoin due to different reasons and spiking up of fees is expected to happen. If we don't want to deal anything with high fees related transaction then much better not to follow the crowd and send while this scenario occurs. Still much better for the fee to subside so that we can get more better experience on upcoming new ATH which people awaits for long time. To many people are happy to see the transaction fee became more lower since at the moment even if bitcoin price reach at $50k they can still transact at anytime they want without worrying about those huge fees that need to spend.