If you can remove it with a finger nail, yes.

ETA it's unusual to see scale on the edge of a leaf, they're usually on the midrib and larger veins. So it's possible you have several things going on. The second pic is out of focus so it's hard to be certain. If you remove one with a nail it should be gooey underneath. Is it?

"I have removed any evidence of them by hand, washed the leaves and flushed the pots with a solution of tea tree/peppermint liquid Castile soap, neem, alcohol, peroxide. i also cleaned the leaves with neem diluted with water (I use this as leaf shine for indoor plants. Lastly, I sprinkled Bonide Systemic on the soil of each pot."

That is quite a bit of counter measures. Poor scales have no hope in hell... Rubbing alcohol by itself is effective in killing most scale but yes, they do show up again and again. I have learnt to live with and control/manage them rather than aim to eliminate them at this point. I find that they can find their way via orchid bark and/or mulch on previously clean plants. They pretty much make themselves comfortable in the potting mix and show up every few months thereafter.

Systemic should help. Exposure to outdoor living can often get rid of them. I think there are enough natural predators even on my 4th floor city balcony to ensure that scale vanishes by the end of summer. Keep an eye out for ants. They are the biggest culprits when it comes to spreading scale around. The ants love to farm them to harvest the sugary substances that scale produce.

floral_uk z.8/9 SW UK, I didn’t notice any goo.

getgoing100_7b_nj, i cultivate C&S, Adeniums, and Plumerias. That is my regular preparation, designed to kill all stages of whatever in one shot. Especially on the balcony! Using a weak solution of neem as leaf shine has been very effective on my Aglaonemas in the livingroom. We are in the Caribbean where humidity is in the 90s and pests are a constant, hence the overkill.

These pothos are in my bedroom along with a variety of Sansevierias, so no ants. I tried alcohol alone 1st (3 consecutive weeks) but it was not effective. These foliage plants are small and new to my collection. I believe they arrived with this scale.

I'm not even convinced it's scale now. Can you get an in focus picture?

No, they have not resurfaced. Grateful they are gone … for now.