If your primary concern is "maximum compatibility" and you only need to use it "once or twice a year" wouldn't Office Online[1] be sufficient to your needs? [N

If your primary concern is "maximum compatibility" and you only need to use it "once or twice a year" wouldn't Office Online[1] be sufficient to your needs? [N.B. - I've never used it, just seems it would suit your use case] [1] https://products.office.com/en-us/office-online/documents-spreadsheets-presentations-office-online https://products.office.com/en-us/office-online/documents-sp...