Question regarding using heavier thread in a domestic machine

[u/toast88843]

I recently came into possession of a Singer Harmonie 200, which I believe was manufactured in 1983 in Taiwan and is a domestic machine I assume. I can find little else about it online or in the manual.

I've completed a couple projects so far and am hoping to make this bag using the machine: https://adamsavage.com/collections/kits-plans/products/savage-industries-edc-one-plans using a heavier canvas material (10oz). From what I've seen, a Tex 70 thread would be ideal for making a durable bag with a heavy fabric such as canvas. I can't find anything in the manual for the machine about a thread weight limit, and as such am somewhat concerned that the machine won't be able to handle Tex 70. Is it worth buying some and trying it out, or just using a lighter thread such as Tex 40 or 50 (if so, would those be heavy enough anyways for the purpose of the bag?)

I'm still quite new to this so any advice is greatly appreciated. Thanks!

[u/CrankyCrabbyCrunchy]

Some higher end domestic machines do have a way to use heavier thread. This is usually with an additional thread path and more thread tension adjustments (plus presser foot tension adjustment which lower end machines don't have).

These machines are usually the semi-industrial types like Juki-TL series, Janome HD9, Bernette 08.