There's 10,000s low marketcap altcoins. To research on the top ranking ones ranked 100-300 one by one is lets say challenging. There's even old coins that haven't surpassed its 2017/18 all time highs bull market highs so these will be risky to hold. I am interested in new projects/trends that haven't experienced a bull market yet.
I think this will definitely be a personal research as things stands now both this tools you mentioned do not have such function on them. On the app which is more easier to navigate you can simply rank them by market cap, categories or even recently added. My advice is you categorize them base on the narrative you are looking for and then look for one’s on top of the new narratives. As for searching by ATH both of these tools so far haven’t added such feature yet. I think you need to write out your narrative and take out time to search them individually, they can’t be in hundreds. Then the ATH of each of them has the date it was recorded that will tell you those that haven’t added new ATH since 2017.