Sight Glass for Stacker Wagon Hydraulic Tank?

I've finally gotten fed up enough with checking the oil level in the hydraulic tank on my NH 1033 stacker wagon that I'm thinking of adding a sight glass to it.  The owner's manual states that the oil level should be 10 inches with all the tables down... and the tank sits right under the 2nd table, so access is a bit of a pain.  I found this sight glass for sale and was thinking of adding it to the tank the next time I change the oil (which it's due for).  Any thoughts or opinions?  Anyone ever done this, already?  I'm not sure if I'm asking for trouble by purposely drilling holes in a good tank.

 

https://northernhydraulics.net/catalog/hydraulic-oil-sight-gauge/oil-level-sight-gauge-1854.html

 

Thanks, Josh

Sight Glass for Stacker Wagon Hydraulic Tank?