Successfully tested a new pen alternative and can report that it works really well on Kobo Elipsa. The writing feel is smoother and feels softer gliding on the glass surface, vs the original Kobo pen. Both buttons work as expected, same functions as the original pen.
The new pen is the Lenovo Precision Pen 2 (Part Number: ZG38C03380). Originally it was meant to be used with an Android tablet (Tab P11 Pro).
The unique feature of this pen is that, in my case, it works with the Elipsa, but also works with a ThinkPad X1 Yoga Gen 6, which uses Wacom AES 2.0 protocol. The pen supports 4,096 levels of pressure and tilt detection. Tested in a few Windows drawing apps, and everything works great, including the tilt feature.
So I've been switching between the Elipsa and Thinkpad writing/drawing with the same pen, because it's capable to switch between two protocols: MPP (N-trig) on the Elipsa and AES 2.0 on Thinkpad Yoga.
Last, but not least, the pen has usb-c port for recharging.
I ordered it from Lenovo Canada for $59.99 CAD here:
https://www.lenovo.com/ca/en/accesso...S/p/ZG38C03380
It is also listed on Lenovo US for $39.99 USD:
https://www.lenovo.com/us/en/p/acces...ets/zg38c03380
Looks to be temporarily unavailable at the moment.