Put email attachment ( though looks a bit innocuous) somewhere safe..that is the official notification and will be required again..gives visa #, it's lifetime and other personal info..there is no longer a full page visa just a stamp on entry with a small "e-visa" notation..
Individual regular Income of the applicant is often the problem with Canadian applications ..and generally one is directed towards "sponsorship" applications otherwise...a much more tedious and complicated process.
However there may be allowances for marriage status, if things have changed.
for others the e-visa for a 6 month multiple entry is considerably different than the older Thai Canadian embassy one (of which I had 6 pre-COVID...loads of documentation is requested other than what is outlined in the application which you pay up front , and can delay approval (out of the Canadian office for some reason) for months ..I had to enter visa exempt , for example.. since flight was booked and only later was my actual Visa application approved and received by e-mail.
My recent experience at Chiang Khong with exactly same type of M (multiple entry) 6 month visa (issued out of Canadian Thai Embassy) was on a Sunday..an excellent day to do it. Not busy and simple straight forward procedure.
Carry Thai baht (do not confuse actual stay and wait in Laos for an actual visa application where often American currency is encouraged)...have available the e-mail print out of your Visa since , though innocuous looking as compared to the traditional plate type insert you will receive on Lao side..it shall be your official visa document ). You will receive 60 days and shall get same for unlimited crossings until visa expiry date clearly marked on your approval doc....also found there is VISA # which you use for your TM6 card (still used at land borders) for re-entry.
If you live far from Lao land crossings ...and wish to get a 30 day extension (example..last stamp before leaving for good) you can visit a local Immigration Office and pay 1900 baht if approved.)
Both processes are quite different though and will be recorded as such.
if doing a true "bounce" as opposed to a regular visa where you would have to stay a few nights to process application:
currency used on Laos side is Thai Baht...(not American dollars suggested for visa application)
on THAILAND re entry..fill out the TM6 slip before approaching Immigration counter..leave exit portion (left hand portion) blank as this will be stamped and stapled in your passport. (TM6's were used in the past for all entry to Thailand..now just land crossings)..
if you know of another..or others..who are doing the same thing, consider getting a Grab driver for the day..simplifies things and wonderful drive back if you go in a loop ..following the Nok River on the way back..then, no need of bike taxis after bus ride...just the very short bus ride between Immigration checkpoints.